Filco modifier problem?

[PointyFox]

Every once in a while my Filco keyboard (PS/2) would start acting like one of the modifiers were being held down when they weren't.
Like tonight when I was playing a game and tried pressing some keys only to have the game minimize, "Library" open, the run box open, Windows Media Center open, Internet Explorer open, etc. and figured out that the Windows key was pretending it was stuck down.  Pressing it again fixed this.
So I opened Aqua Key Test and noticed that when I pressed the left alt key plus modifiers, the arrow keys, or 6 keys above the arrows, that these other keys would appear to stick.  However, when I tried this on the desktop, they didn't stick.  If I press multiple keys (a lot) plus modifiers, sometimes the modifiers would stick (left shift, right shift, right win, right menu, right ctrl) (not just in Aqua Key Test).  Though it has also happened a few times when playing games.

Does anyone know what could be wrong or have similar experiences?

[rowdy]

I get that once or twice a week with a Ducky Shine on Windows 7.  I've had it on the same computer with older keyboards too.  I figured it was just Windows being Windows.

Pressing each modifier a few times seems to clear it.

[PointyFox]

Yeah, I have Windows 7 64 bit.  No idea if it is a Windows problem.

[rowdy]

I used to use an Apple aluminium keyboard on this computer and had the same sticky modifier problem.

I thought it was the keyboard, and eventually replaced it with a Microsoft rubberdome keyboard (yes, Microsoft hardware).  Same problem.

Now I have the same thing with a Ducky.  An equivalent Ducky on my Mac at home does not do this at all.

Therefore the prime suspect is Windows.