Comment 55 for bug 568988

http://blogs.amd.com/play/2010/06/16/ati-catalyst%E2%84%A2-10-6-driver-%E2%80%93-what%E2%80%99s-new/

New driver from ati (10.6) works perfectly and finally ATI addressed this issue.
I have Mobility Radeon HD 4500 (Dell Studio 1555).

Eerlier on I suffered from a different bug:
https://bugs.launchpad.net/ubuntu/+bug/574848?comments=all
which was fixed with previous Catalyst 10.5.

I've just uninstalled 10.5 and installed 10.6 - now the system properly resumes and finally feels sleek :)