If you see a glowing pink around the windows on Ubuntu 8.04 then you are not alone, it’s the result of a bad symlink in the nVidia driver. Here is the solution.
sudo rm /usr/lib/xorg/modules/libwfb.so
sudo ln -s /usr/lib/nvidia/libwfb.so.xserver-xorg-core /usr/lib/xorg/modules/libwfb.so
Then restart the system. Thanks to bigtomrodney from Linuxforums.org
ubuntu — May 7, 2008