I used to have that happen it would not recognize it till I unplugged then re-plugged the keyboard then it would find it and work, luckily I have a KVM switch on my desktop so it was easy to get to do do this, I love a wireless mouse but just can not get a good wireless keyboard that I find worth the effort so I use a wired one with virtually no problems, I mean it is on my desktop just how far will I be going with it anyway. Also make sure the receiver is not blocked or out of line from the unit.

Advice/suggestions from a layman: Control panel>mouse> open it up and do some changes then put it where you want it and try. Control Panel>keyboard . move those sliders around and check it out. Vacuum out the keyboard. I have a lap top, but I use a external mouse and keyboard as I have it set up similar to a PC. Not very portable, but it is seldom used outside my home. Grady

It's not uncommon for there to be a mechanical problem with one or two keys. You could have dropped a few crumbs in there or a couple of drops of coffee. You can try to blow under it with some compressed air, or carefully pry off the keys to inspect for problems. It could also be that the contacts are broken and you need to have it repaired. Have you talked with Dell? Is it under warranty?

Strange thing is my netbook and office desktop work fine, no backbutton problem. All had the same updates and version FF. Tried my husbands laptop and it works fine - same updates. All run XP. Nothing different that I can tell. The problem continues on my home desktop. I can't figure out what the difference would be. I don't think its the mouse as I use a wireless MS mouse. Jane