OpenGl unstable

hi, I have a voodoo2 3DFX card.
Since I had my computer upgraded to a 650Mhz Duron The openGL option seems to be unstable,
If I play Soldur of fortune, star trek elite force or Half-life, (all games witch never had problems before) I can play fine, But if I try to quit or change settings The screen goes dark (not black)and the system hangs…
If I try installing the latest drivers, after installing it restarts windows and freeses, the only way to get into windows again is thru safe mode. any ideas anyone?
Please help,

Somehow I don’t think it’s OpenGL’s fault =) I had some problems with my Voodoo 3 PCI a while back. Just buy an nVidia. =)

But I never had any problems before, Its since paul upgraded the drivewrs I’ve had the problems…
Besides, I just spent $1,200 on the upgrade, I can’t afford a new card.
Are there any possible solutions?