Well, it can't hurt to call HD, but I think 4 years is an awful long time before filing this issue for remedial action. Don't be surprized if they say "not our problem."

So I understand correctly. Your kitchen was redone in 2003? The kitchen is at least 4 years old including the silestone? If this is the case I'm not sure HD is going to do a thing for you. Was the work warrantied in any way?
I hate to say it, but I think your out of luck. If you noticed all these things wrong back in 2003 and didn't say anything what makes you think 4+ years later they will even entertain your call?
I wish you the best of luck and I'm sorry to hear about your predicament.

Most likely your counters or floors have settled, resulting in one section of them being lower than the other. Settling isn't covered by any warranty from anyone. If it really bothers you, then contact the original fabricators to come and reset the counters, but it will be at your expense.

It's a very easy DIY project to remove the grout at the wall seam and fill with silicone. It won't even take a day's time.

teedup1, rockpig and live oak thanks for your replys. I wanted to hear if anyone thought it was resonable for me to expect HD to fix it after 4 years. I will have to get my papers out to check on warrenties. I know Silestone has a 10 year garrantee on the material itself but I don't know if HD has any on the installation. I did not notice the uneven seam until before Christmas this year---they may say it is caused by the house settleing.

The installer not templateing----I just thought it was how he did it since he had been in business for a while and I did not question him. At the time I was so happy to finally getting the counter since there had been problems/changes with a wall oven cabinet not fitting--then had to change to a slide-in range--I took that this was an ok way to do it. This kitchen fire was devastating and I had to make so many decisions so fast and had questions thrown at me from all sides (insurance, fire inspector, contractor, cleanup folks, HD, Sears,ect). Except for the piano and beds our entire contents was emptied--we camped on our back enclosed back porch.

These are problems I can live with--noone else notices it unless I point it out. I will call HD to see if they will do anything.

As of a year ago when I worked there... :)

Home Depot has a One Year Installation Warranty.
If you call them, ask for either the specialty manager, or the kitchen expeditor. Explain to them that you are having numberous problems with products which were installed by them. They should put a call into a dispatch center, which will get a Field Services Manager to come out to your house and take a look at your issues.
The FSM is employed by Home Depot, and they can't charge you for him coming out. His job is to look at the situation and determine if your issues are caused by their installation, or "natural" causes - i.e., settling.
If he thinks that this was not caused by their install, he should still be able to get you in contact with the Silestone company to set up doing what they can do. There may be a charge for this - but if it goes through the H.D. where you bought it, it might be cheaper than trying to contact the company yourself, and if you get the manager on a good day, they might be willing to help you out with the price.
As far as template vs. measuring - if it was a square/rectangular piece, I think measuring isn't totally out of the question. Even with templating, they don't necessarily scribe the countertop to your wall, but they might make the top deeper and recess it into your sheetrock so that there are no gaps.
I think that I would have the FSM come out and look (if your H.D. is willing to work with you) As far as something that you can do yourself, to chip out the offending grout, and fill with silicone at this point, wouldn't be too difficult, at least to get one thing solved and out of your hair :)

Hopefully, things haven't changed too much and that I've not led you astray - but I think it's worth following up!

It'd be worth following up during that one year warranty period. Not 4 years later. Any big box store will have had a complete turnover in personnel from the KD to the Store Manager and no records will exist that far back. They'll refer you to corporate, who will refer you to the one year warranty period being expired and that'll be that.