Keyboard/mouse not reacting sometimes...

Hi I have a strange problem.
My mouse and keyboard are working without a problem most of the time. But sometimes (no specific situation, can’t reproduce) there’s a bug and the mouse is jumping around for 1-2 secs and the keyboard is pressing like all keys at once. After those 1-2 seconds its possible that either the keyboard or mouse or both don’t react anymore, and I need to restart.

Never noticed anything like that with WindowsXP or Ubuntu (last one tested was 8.10).

I’m using 11.2 with KDE 4.3.5 and a Microsoft Wireless Desktop 4000 connected via PS2.

PC: Athlon64 3400 1,5 GB RAM, Geforce 7600GT (using Nvidia drivers)