Re: NVIDIA, GLX problems
Have you run 'emerge sync'?
If you did, you've probably gotten a newer version of your kernel source. From there you really have 2 options
Recompile your kernel from the updated source, then install the nvidia modules
change the symlink for /usr/src/linux to point to the version you're running and re-emerge nvidia stuff.
Option "RenderAccel" "true"
If memory serves (in win ATM and can't connect to Nvidia FTP) RenderAccel is classed as experimental. I would suggest you worry about getting it running properly before you start tweaking.
VendorName "Monitor Vendor"
ModelName "Monitor Model"
You might want to at least set your horizontal and vertical refresh rates, just to make sure you don't pick a mode thats out of spec and fry your monitor (Yeah, I know that's a really cool whine and the puff of smoke looks nice, but can be an expensive way to experiment)