Ok first off let me say, I AM NOT AN EXPERT --> I AM A NEWBIE TO LINUX
however, I have the same card (Radeon 9500 pro)
My version of linux is Mandrake 9.1 which means my (I believe kernel version) version is 4.3.0
# X -showconfig
to find out yours
the drivers provided from the www.atitech.com
site are for 4.2 and lower, hence why they won't work
many people have suggested using the XGL1 drivers from schneider.de
I personally haven't had any luck with these yet, but if you search the forums using appropriate key words you should find a link to the drivers without much problem!
BEWARE though you may have the same problem that I do, I that X won't start after installing the XGL1 drivers.
if you find or have found a solution to your prob please let me know