Comment 14 for bug 494699

The drivers available from the official AMD/ATI website do not yet support the lucid kernel / xserver - use the packages that just got pushed to the lucid repositories (which basically is a unreleased catalyst) - you may have to wait a few hours until all mirrors are up-to-date, or you can take a look over at https://launchpad.net/ubuntu/lucid/+source/fglrx-installer/2:8.721-0ubuntu1 .