I'm getting this problem too on Kubuntu 7.10 with the fglrx driver, not using any compositing window manager. The weird thing is that it worked soon after I installed Gutsy, but just today apparently it decided to stop working. Gutsy also keeps switching my driver from fglrx to vesa for some reason. I have to say this seems like the buggiest ubuntu release ever.
I'm getting this problem too on Kubuntu 7.10 with the fglrx driver, not using any compositing window manager. The weird thing is that it worked soon after I installed Gutsy, but just today apparently it decided to stop working. Gutsy also keeps switching my driver from fglrx to vesa for some reason. I have to say this seems like the buggiest ubuntu release ever.