Hanging on exit

[mabonus]

I'm using a Voodoo Banshee on Mandrake 8.2 with a 2.4 series smp kernel, 
and openGL/Glide/hardware acceleration works fine, but whenever I exit 
some games it looks like control is not regained, and the only thing 
the video card outputs is the last frame drawn.  Here is what I have 
tried:

vendetta - Works fine, a few bugs, but I don't think it's the drivers, 
just the game.  Exits beautifully

bzflag - Didn't regain controll.  Logged in with ssh and killed bzflag, 
kde, X, etc, but never got the display working again.  Rebooted

tuxracer - Same thing, rebooted

quake2 - Worked fine, till I tried to exit.  Hung there, but a kill -9 
for quake2.x86 killed quake and left me in 640x480 resolution, which I 
could change out of

Any thoughts on why this might happen and what I can do to prevent it?

James