I have a powercolor 6870 which works perfectly in lion; however I have to send the card back for repair as it's defective. When I switch over to HD3000 graphics (i have to do this in bios) with the card installed, windows works fine but lion either freezes at gray screen or kernel panics depending on graphicsenabler (=yes/=no, respectively). I think OSX may not like having 2 different adapters installed concurrently, not sure if there's any way around this. If anyone else has any input it would be greatly appreciated!