Krazy Keyboard

I'll preface this by saying that I have run numerous scans, including with AVG, Spybot, Spywareblaster, and MalwareBytes.  Nothing found.

I have an Inspiron 530 with the Dell multimedia keyboard (Dell P/N TH836).  A couple of weeks ago, the keyboard starting acting funny...almost as if random keys were getting stuck.  I'll give a few example situations.  If I was in a folder of pictures and using my arrow keys to move to the next picture, things would be fine for a while but then all of a sudden the arrow key would act like it was stuck and it would move all the way to the last picture in the folder.  Similarly, if I was browsing the internet and using the backspace key to move back a page, out of nowhere it would be like the backspace key was stuck and I could watch as the browser went back through each page I had been to all the way back to my homepage.  I did all of the aforementioned scans, backed up everything, and eventually the problem went away or so I thought.

A few days later I got my Windows 7 Ultimate upgrade disc and painlessly upgraded.  Shortly thereafter the keyboard problem has reappeared with a vengeance.  I might be typing something into google or the address bar and a random letter will appear to be stuck to the point where I can't even delete the letters fast enough.  More often than not, after a restart I cannot even type my password at the login screen or press the Function keys to enter the Bios or Boot Setup before that.  Nothing happens when I type.  If I do press a lot of keys to get a response from the keyboard, one of them will inevitably get "stuck".  None of the keys appear to be physically stuck and I've taken many of them off to check and clean them just in case.

Other things I've tried:  Removed keyboard from Device Manager and plugging it back in to reinstall.  Tried every USB port that I have.  My wife has an Inspiron 530s with the regular keyboard (Dell P/N SK-8115) which works perfectly when connected to my computer.  Additionally, my multimedia keyboard has similar problems when connected to my wife's computer or my work computer (Dell Optiplex 755).  I don't understand what could physically be wrong with the keyboard since all the keys seem in working order and it's totally random almost as to which key will be "stuck".  So I thought it must be a driver or registry issue.  I haven't installed any programs recently that could cause this and there haven't been any obvious Windows Updates that might cause this either.  So I'm at a loss as to what to do.  Are there any steps I can take to complete remove all traces of the keyboard from my system so then I can try and "reinstall" it fresh?  I've tried removing it from Device Manager as noted.  Is there something in the registry that I can remove too?

I'm resigned to the fact that I'll have to get a new keyboard and I'd like to get the same one I have now but not if it's going to have the same problem.  Thanks for any help!