do any OpenGL programs run ? i.e. run glxinfo and see if it runs.
If it does run, check to see what the OpenGL renderer string is, Mesa or ATI, if direct or indirect rendering.
At the moment the ATI driver 8.25.18 doesn't load properly on my IBM T42p machine,
glxinfo
name of display: :0.0
[fglrx] API ERROR: could not register entrypoint for SelectTextureSGIS
...
Using the Mesa/Xorg default ati driver should start up, but may not support all functionality, should be better than nothing at the moment.