This is probably old news for many but it was annoying me for some time so if it helps anyone else it was worth posting 
My wife's PC has an XFX 5830 in it, actually have two but could never get crossfire working on it. Anyway it permanently had random green pixels on the desktop but seems fine in games i.e. 3d clocks. I had a look around some time ago and couldn't find an answer and wondered if the card had had it.
Anyway I had another go today and found this http://www.techpowerup.com/forums/threads/updated-amd-ati-2d-clock-guide.117633/
This 2d clock fix worked a treat. No idea why they set them so low by default but I'm not running 300/575 2dclock/memory and it is perfect.
Hope it helps anyone who experiences the same
My wife's PC has an XFX 5830 in it, actually have two but could never get crossfire working on it. Anyway it permanently had random green pixels on the desktop but seems fine in games i.e. 3d clocks. I had a look around some time ago and couldn't find an answer and wondered if the card had had it.
Anyway I had another go today and found this http://www.techpowerup.com/forums/threads/updated-amd-ati-2d-clock-guide.117633/
This 2d clock fix worked a treat. No idea why they set them so low by default but I'm not running 300/575 2dclock/memory and it is perfect.
Hope it helps anyone who experiences the same