Matrox g550 support

When debuging problems with my NVIDIA graphics card, I have decided to test also Matrox G550 (dual head) card in my Opteron machine (running Suse 9.1 64bit). I'm able to run Xserver, but without GLX support - libdri.a has unresolved symbol __glXActiveScreens and I don't see libglx or libGLcore other then comming from nvidia drivers. Is GLX supported for Matrox G550? Did I missed some package I should install? Thanks Mirek Ruda