Isn't that a new keyboard?? {I could be thinking of someone else though}
I'm thinking same as you -a leftover part of that virus popping up at times.

The only real fix I can think of .. is start saving any important files and your bookmarks /favorites to a CD.

When it gets too frustrating wipe the hard drive and do a complete format then reinstall windows - all fresh..

{only if you have a Install disk though -- Oh -did you make your restore disks last month when it was asking you to do it?}

I've started over many times and it isn't as bad as it seems, the worst part is losing things that you didn't have backed up.