Wow! I thought I was the only person this happens to.

I feel pretty comfortable saying that it is not the keyboard. This happens on my laptop as well. In fact, the EXACT same symptoms. The first time it happened, I thought I'd picked up a virus, so I scanned the bejesus out of this laptop and found nothing.

It is a company laptop, so the second time it happened, I called the hardware services guys. Several days later, some dude came out, looked at it for about 10 and a half seconds, and told me it was my keyboard, and he gave me a new keyboard.

About a half an hour later, it happened all over again.

It has since happened when no keyboard was attached and I was using the laptop keyboard.

Something is screwy with my laptop, and it sounds like something is screwy with yours as well. If you want to try the same experiement, then use your laptop for a while without the external keyboard and I suspect you will get a runaway key again.

What kind of laptop do you have? I have an HP.