I'm playing Quake 2 v3.20 using my Dell Dimension XPS M200s (see sig) with a pair of Creative 3D Blaster Voodoo2's (CT6670).
I'm able to successfully take in-game screenshots at 640x480 and 800x600 in both single-board and SLI mode. However, if I increase the resolution to 1024x768 (SLI only) and attempt to take a screenshot, Quake 2 freezes. The game plays very well in 1024x768. Taking screenshots in this resolution is the only issue I'm experiencing.

I'm using the Creative 3D Blaster Voodoo2 retail CD drivers (02/98) and have also tested both 3DBV-95WEB-1-US (05/98) and 3DBV-95WEB-2-US (03/99).
The Retail drivers freeze the last Quake 2 frame on the screen, resorting to blindly control Windows 95 behind the scenes so I can successfully reboot and recover.
Both later drivers are able to crash out back to Windows so I can successfully restart Quake 2. They also report a page fault in the stack trace that points to 3DFXGL.DLL being the culprit.
I installed Creative's last beta MiniGL driver, vd2gl.exe (05/99) which only adds an opengl32.dll to my Quake 2 directory. This allows me to use the "Standard" OpenGL driver and this can successfully take a screenshot @ 1024x768. It does not update the existing 3dfxgl.dll.
I'm also able to successfully take screenshots using my PowerVR PCX2 card, using Quake 2 built-in PowerVR SGL driver.

However, I'd like to know why the 3dfxgl.dll driver (13/02/98) is not able to handle screenshots @1024x768.
Does anyone know of a later 3dfxgl.dll than the one above, which may solve this problem?