We do the same thing with the girls. When one of them is having a mental meltdown over every little thing we simply say "It's totally OK to be upset but your tantrum is disrupting dinner,TV time, homework, so if you must throw a fit go to your room and throw it."

They almost always turn it off immediatly. When the bevior doesn't ge the reaction they want (attention, their way) they stop it. It's actually a funny thing to watch. The tears go from 60 to 0 when they have to decide whether to calm down or go to their room.

Really, I can't say there is a method I can claim works. Like putting together a puzzle, I just keep turning the pieces and hope it works. The last weekend Eric was here. He was asked why he tore up a piece of paper and threw it on the floor he'd just watched me vacuum. Honestly, I expected he'd shake his head say "I don't know what I was thinking" just pick the paper up and put it in the trash but this turned into an all night ordeal because when asked, he chose not to answer. He just stares past me like we don't speak the same language and he has no idea I was speaking to him. So his dad gets involved, explaining that when spoken to, he needs to answer and he ignores his dad so his dad sends him to his room. Before the night is out he's bursting out with lines like "lets just put it this way, if there was an award for the worst kid in the world, I'd win it!" And Dad and I say I'm sorry you feel that way and Dad goes on about how he needs to respond to people and Eric sits there acting like he's listening and then he'll come up with something WAY from left field. I can't even remember what, it was completely irrelevent to the topic and just antagonistic on his part, so I say "I think it's time to get your PJ's on" and he says "GOOD! Don't ever talk to me again"(directed to both dad and I)-- Dad and I just look at each other and shake our head, he's SO ANGRY at the world. What should have been so simple as picking up the paper and putting it in the trash turns into a 2 hour, entire evening killing crisis.

That is just one situation, typically his fits are accepted with "It's okay for you to be angry, how you conduct yourself and work your anger determines the outcome" We have encouraged him to use direcet statements and express his feelings when he feels wronged by one of the other kids. It's a long time before hes calm enough to talk it through so this process is time consuming. Sometimes his anger is so big he doesn't care what the consequence is he just keeps it going.

And some days he's a helpful, kind, thoughtful pleasant kid to be around. I Wish for more of these days.

I'm pretty sure most of the time he is NOT "out to get me" I'm also pretty sure every now and then he actually is. Most of the time I know I'm being hyper sensitive and that's why I admit the foolishness here :)

The truth is when Eric says things like I'm the worst kid in the world he really wants to hear "No, you're not" and all the loving reassurances that will follow. If we give that while he's being disciplined doesn't that send the message "If you behave badly or act out you'll be rewarded with 20 minutes of our undivided attention and a good talking to?"
I don't know, I don't have any answers, I just keep turning my pieces.

I read on a different thread that most prents see their bio kids as angels with gleaming halos and their step kids as undisciplined brats--not a direct quote just summarizing. I want to say my kids have thier days too. The day my Husband had had enough of my daughters tween attitude and eye rolling I went straight to her and told her that her behavior wouldn't be acceptable and I wouldn't hve her attitude causing problems in my marriage. My son is hyperactive, rarely hears more than the first and last word of anything said to him and can be really annoying at times. I love them all, they have their own issues. I just wanted to say my kids aren't perfect either.

This is a NOVEL. Sorry...
But I know you're frustrated and since we've dealt with many of these issues with quite a lot of success, I'm going to share it all.

A__ has pulled stunts like the paper thing too. We stopped giving a big response at the time, and he can go sit in his room until he's ready to pick up his mess / eat his supper / be nice / etc. Then we talk about it afterward, calmly and rationally.
For awhile, A__ was going to his room AT LEAST once a day, often more. Once he went to his room five times in one day! He stayed in there until he was ready to correct whatever behavior, so it was totally up to him to choose to behave. Once he was in there for an hour and a half!

I know that all the parenting logic says to address a problem behavior immediately, but for a kid who is seeking negative attention, that's just feeding the problem... So we wait until after, when A__ is calmed down and he has had a chance to think about what his bad and good behaviors were. It also gives us a chance to mellow out about whatever he did, so that we're not mad when we discuss it.

Now, A__ has come a looooooong way, and has only been sent to his room once in the past two months. He was in there for about ten minutes and then he was ready to come out and apologize/talk.

"Sometimes his anger is so big he doesn't care what the consequence is he just keeps it going."
This was a HUGE HUGE HUGE problem for A__. If he got angry, it was the end of the world. He would yell, and say he hated us or that his dad was the worst dad in the world. He would scream that he wished he was dead because he was being tortured. He would throw things or hit or kick at whatever was near him. He would get so enraged that his face would turn purple and his pupils would fill his nearly whole iris. It was awful and scary.
He is still struggling with anger management, but things are a million times better. He hasn't been mad like that in a good four or five months!

How did we do it?
We started giving anger management ideas when A__ was totally calm, or a little peeved about something minor but not MAD. We'd suggest things like deep breaths, picturing your anger like a big red balloon that you don't want to pop, running the other way to get the 'burst' out, tell/ask someone to stop whatever is making you mad, say that you're getting mad when you feel it coming, let out a quick yell or scream to get the 'burst' out, etc etc.
These alternatives were very gradual coming into effect... He "knew" them in his head, but it was awhile before he could really put them into action. So when he'd get mad we'd talk about what else he could have done, how else he could have reacted, how he could have prevented a freak-out. Gradually, very gradually, we saw him begin to use them. One day when he was getting mad, he took a few deep breaths, said "BIG RED BALLOON!!!", turned away for a few moments and was OK when he turned back to us - that's when I realized we were getting through on anger management.
Keep on keepin' on for this one. I thought we'd never get through to him, but we are.

When A__ says something like "I hate you and I wish I were dead!" or "I'm the worst kid in the world!" we don't go into 20 minutes of undivided attention anymore. We quietly say "That's too bad, because I love you and am glad you're alive" or "That's too bad, because I think you're pretty great" and quietly tell him that when he is ready to be calm, we are ready to talk about why he is upset.
If he keeps up the drama, we just repeat "I only want to have a nice conversation, without all this drama. We can talk when you have calmed down. Please go to your room to calm down and come out when you feel like talking."

Sometimes, when we are talking about his anger or bad behavior or whatever the problem is, he doesn't want to look at us. So as long as he is speaking clearly enough to understand, it is OK by us if he wants to hide his face behind a sweater or pillow, or if he wants to crouch behind the chair, or hide under a blanket. It makes him feel more comfortable and he is more likely to talk openly than just say "I don't know" over and over.
We do usually ask him to look directly if he has to apologize for something though... for more accountability and ownership of your actions.

"He just stares past me like we don't speak the same language and he has no idea I was speaking to him"
This sounds familiar to me, but is one that we haven't had as much success with.
IMO, we haven't been successful because I don't think it's something he really realizes he is doing. He realizes it when he is getting mad, he (usually) realizes it when he has a bad attitude; he may not realize it when he isn't acknowledging someone.
I honestly think that A__ gets in his "bubble" and doesn't notice what is happening around him at all. The bubble is more impenetrable if he is hyper-focused on something, such as a computer game he enjoys or something that is bothering him.
I've found that he is more likely to snap out of his bubble if more than one sense is activated... So I speak to him while moving around in his line of sight or touching him and he is more likely to notice. He is also more likely to react poorly, but you've gotta take the good with the bad...

As for the distinction between positive and negative attention... We had a little "workshop" on it. We chose a time when he was relaxed and was having a good day with good communication skills. We started with that we weren't upset with him and that he was not in any trouble, but we wanted to talk about looking for attention. We call it "good and bad attention" but we sat down to talk about it, and went through examples of real recent behaviors, and hypothetical behaviors, getting A__ to identify which it was. Once he appeared to understand the difference, we got him to come up with "good attention" alternatives to "bad attention" examples.
We talked about that doing things to be nice, helpful, polite, mature, responsible etc - anything that someone might give you a compliment for - is "good attention". We talked about that doing things so someone will tell you not to or to make someone mad/sad/annoyed is "bad attention".
We talked about how to identify if you are looking for attention - that if you are bored/lonely/mad/sad and want someone to notice or entertain you - and how to get their attention. If you are bored, a "good attention" way is to tell them you are bored and ask them to play with you please; a "bad example" way is to throw things at them until they get mad at you. If you are mad, a "good attention" way is to say that you are feeling mad and ask to talk about it or excuse yourself to your room to calm down; a "bad attention" way is to stomp and shout until someone asks you what's wrong.
Now, all we usually have to say is "Are you looking for good or bad attention? Can you try again with looking for good attention, please?" and he does. Sometimes it takes more coaching and work, but at least half the time, he can figure it out himself now.

"Eric sits there acting like he's listening and then he'll come up with something WAY from left field"
A__ does this as well. It usually indicates that he is at his max for this particular thread of the conversation and it is time to change angles or ask for his opinion.
It helps to keep him on topic by asking him frequently to rephrase what we said into his own words and tell us what he thinks about it.
I find it frustrating and tedious, and FDH can hardly do it... But it helps keep A__ on the conversation instead of wandering off into left field.

Of course, we praise praise praise until we are blue in the face when he makes good choices and shows good behavior. It feels like I tell him 500 times a day that he is using nice manners, or being thoughtful, or listening well, and so on... But even though I am sick to death of saying "Thank you for doing what you were asked the first time!" or giving high fives for little things like tidying up his own mess, I keep doing it. I figure that if I'm not sick of praising him, I'm not doing it enough to reinforce the good choices.

Some other posters (mostly those with "easy" kids) think that our incessant yammering at A__ about good behavior and our many approaches are stupid and too complex... But like you, we are turning puzzle pieces, trying to find what fits. It's hard. People whose BKs or SKs have had no major behavioral problems don't understand the conscious level and planning that it takes to approach a child with behavioral problems or disorders. But don't lose hope yet! We've seen amazing, astounding, exponential change in A__ since we decided to develop a parenting plan, and started looking for the puzzle.
Eric sounds so much like A__ of a year ago, and had someone told me how he'd improve, I doubt I would have believed them. I never dared hoped for this sort of turnaround - all I was hoping for was to not be on eggshells all the time, wondering when the next eruption would be... But now we have a wonderful and pleasant boy 90% of the time, a slightly surly boy with a bit of an attitude 9%, and a little monster 1%! It's amazing and I've been surprised by A__'s commitment to behaving better many times.
I've also been surprised at the amount of work it's been for us, the amount of help we've needed from friends/family/GW, and the amount of tears I've shed... but so worth it.

Ah, please don't apologize for a novel...it's easy to go on and on and I apreciate the tips as well as knowing I'm not the only one in the world facing this issue.
You're right, people who haven't experienced children with behavioral issues or anger management issues don't understand how consuming it is to plan your whole day around a melt down. It's not a matter of me disliking my undisciplined stepson. His own Dad sees he's different from other kids (MOST other kids not just mine) and knows he's a handful.
Thanks for the tips and support, I am glad to hear it can get better. Eric will be back on Friday so we'll see how things go :)