Re: 8800 GTS - I should have waited.
in your grub.conf or lilo make sure you take out any vga= lines so it defaults to 640x480 console, that should do it.
It's not as nice but it is what you need to do to end the black screen.
It looks like the reason you are working with beryl/compiz is you are using xgl. I was trying to use them directly through the TFP rendering path which the driver has supported directly for the last couple of versions. This works fine on a 7800 GT with this same driver, but not with the 8800 GTS, at least, not in 64 bit as far as I can tell.
Your xorg.0.log in the bug report shows that you haven't started Xorg since September 19, so I'm guessing you upgraded to XGL sometime around then and have been using it since, I don't think that 6.9 worked with XGL if I recall, believe it only works with modular xorg.