I am maybe dumb, but i don't think vista handles opengl "(that well)" and are using dx10 drivers insteed?
Depends if your vendor actually supplies drivers or not.
The rest of us already upgraded to an earlier version of windows.
When I briefly had vista on my laptop with nvidia 5400 go, fte+opengl ran fine. it was d3d apps that randomly went pure black and didn't recover even after restarting them.
I then upgraded to windows 2000, but had great dificulty finding working drivers.
Seriously, Linux has better driver support these days.
Looks like issues with the depth buffer not being cleared, considering that the centerprint text has no problems appearing.
I'm not sure why the status bar has a nice clear bit around it.
I assume you've already tried toggling the value of gl_ztrick? If not, try doing it. On modern hardware, a value of 0 typically gives better performance, with 1 as the default in ezquake. Toggle it, see if anything magically gets fixed.
I've not tried ati drivers myself in vista, so I'm probably going to be compleatly wrong here. Aaaanyway, if you're really lucky, you might have a control panel thingie for your display settings. If you're lucky, you might find some setting to force the depth buffer precision, which might help. Alternativly, you could find that enabling antialiasing will help too. Then again, you might also find that Vista is such a pile of crap that the drivers are no longer able to support such overrides.
I believe that ezquake uses a stencil buffer, while fuhquake does not. Thus, switching engines might fix it (wether then engine is written correctly or not). You could also try FTE and tell it to use antialiasing in the engine. Just anything to change the number of different planes in the video/depth/samples/stencils buffer.
If you're still stuck, then you might be lucky enough to find a version of FTE that has d3d support, but beware that those builds are quirky, and d3d is currently broken in the FTE source tree.
you may even have to wait it out and just constantly keep updating your video drivers until it finally works correctly. Good luck if you have a laptop chipset. :/
But even so, Vista is such a pile of poo that you'll have inconsistant framerates whatever you do. Linux easily has higher framerates.
Apparently, Vista no longer has 3d hardware acceleration of DirectSound either (not that quake uses that anyway).