I have a problem on my Win 98 PC, where the tab key will sometimes stop working. If you are entering data, instead of tabbing from one field to another, it will start tabbing between programs instead, as if the Alt key were also held down. It doesnt happen all the time, and is cured (temporarily) with a reboot, but it is annoying as it slows work down. I have reinstalled Windows, and changed the keyboard - no change. Any ideas?