Really weird glitch on my comp

All buttons on the right hand side of centre, but not extreme right don't work atm. This happens occasionally, but more often recently, i've rebooted, etc... and found nothing I can think of wrong. Like on this site... i can click on topic names on the left, but the quick jumps on the right won't do anything. Also in WMP and Divx the seek button won't work in that area, but if i move the window to the left, everything works fine. Any help would be appreciated.

 

I can't really help you if you don't tell me your OS

 

vista...
i fixed it by restarting, but that doesn't always work, it'll be back within the week.