I have this problem as well on Natty x64 using Ubuntu Classic with no effects on a Dell XPS 410. It has happened with Firefox, Thunderbird, Terminal, Libreoffice, Evince, and Nautilus,. I have an Nvidia card, I am running with the Nvidia 173 driver. I guess I'll try the current driver to see if that helps.
I have this problem as well on Natty x64 using Ubuntu Classic with no effects on a Dell XPS 410. It has happened with Firefox, Thunderbird, Terminal, Libreoffice, Evince, and Nautilus,. I have an Nvidia card, I am running with the Nvidia 173 driver. I guess I'll try the current driver to see if that helps.