I had a similar(?) issue, but for me the entire firefox window was black (everything except the window decorations). The blackness depended on the size of the window, so when I resized the firefox window the contents showed for certain sizes.
I managed to solve it, by using nvidia-settings and turning on "sync to vblank" for everything (there are three or four of these checkboxes) and then restart X. Now firefox works.
I had a similar(?) issue, but for me the entire firefox window was black (everything except the window decorations). The blackness depended on the size of the window, so when I resized the firefox window the contents showed for certain sizes.
I managed to solve it, by using nvidia-settings and turning on "sync to vblank" for everything (there are three or four of these checkboxes) and then restart X. Now firefox works.
This is ubuntu 7.04, with compiz-fusion installed according to http:// ubuntuforums. org/showthread. php?t=481314