you need to provide more details
what steps did you take to set it up?
kernel version?
X version?
anything you can think of can't hurt - you have 25000 characters to work with in linuxquestions.org.
elaborate
i am not sure if i can help you or not as i am a bit of a newbie myself, but i may be able to as i only just installed my radeon 9600se the other day. mind you, i have not got 3d acceleration working yet - i am working on that.
-daemonTED