Problem With Left Ctrl, Shift, Alt, Win

I have a somewhat strange problem here with the left corner of my keyboard and renoise. Left ctrl, left shift, alt and left win simply aren’t recognized. I cannot use any of the many useful shortcuts that are assigned to these ones. When I go to the “New Assignment” field and press one of them renoise doesn’t do anything.

This happens with renoise 1.5rc1, win xp home, sp2.

do you know if it did happen with previous versions too?

I installed the older version now and gave it a try. It’s nearly the same problem there: the lower left corner keys don’t work - except LWin this time. However, all other windows programs do fine.