While it's true that nVidia drivers are typically easier to get working, the ATI drivers are getting easier and easier all the time. The important part is to make sure you follow all the instructions carefully.
The best howto I've seen is on RedShirt's website here
In case you're wondering, the biggest problem with the ATI drivers is that they assumed certain features/packages were installed and enabled.
Anyways, if you have any more problems, post specifically what problems you have and, where apropriate, the output of glx_gears, fgl_glxgears, and glxinfo.