This is my first post, I just joined, and I hope I've put in the right forum. I have a Dell desktop that's about 4-5 years old, running windows XP. I think this might be a keyboard issue - this my 2nd Microsoft natural ergonomic 4000 in 2 years, the first one stopped responding to certain keystrokes pretty early on, and this one has been fine up until recently, when the cursor started taking off on its own, as if I have the space bar pressed down. I do medical transcription and bang away at this thing pretty hard every day, but I ususally get a couple years out of my keyboards. It happens often, but I can't connect it to anything specific. I cleaned with compressed air prior to this problem starting, could that be it? Or is this another problem entirely, maybe a setting I've changed inadvertently? It happens whether I'm typing in Word, e-mails or IM's, even here, it just did it while I was typing this post. Sometimes I'll look away, look up, and I'm halfway down the page without touching anything. I thought I would ask before I go out and buy yet another one. Thanks for any advice!