Wrong forum - this should be on the end-user board, if anywhere. OpenGL is just a specification, it doesn’t write drivers.
Your best bet would be to contact ATi, but to be honest I think you’re probably out of luck. I’ve heard that ATi threw out their old driver codebase and started afresh recently, and since they have spanking new cards out and drivers have always been perceived as their weak point, I’d guess that they’re going to be focussing on improving support for newer hardware rather than obsolete stuff.
If it’s any consolation, I’ve had the same problem with a Rage LT Pro laptop under Win98; it’s not just a Mac problem.