mslinn; are you running the appropriate aticonfig command after install ? Going from memory, but I think it would be something like :
sudo aticonfig --initial=dual-head --adapter=all
If you run aticonfig --help and look at the end of the resulting output you'll find details on these options. Further up are options to let you control where the screens are placed.
You *might* also want to disable RandR support if you're using multiple cards -- not sure if that is still required or if we figured out how to make RandR (which is still single-card oriented) coexist with multicard support -- but make sure you're running the right setup commands first and let us know what happens.
Last edited by bridgman; 11-01-2009 at 10:02 AM.