The latest drivers need to be 'activated' for 3D. The file tells you to install them in a particular order and then run the "switch2nvidia.glx"(sp?) file to activate the 3D.
I have tried it two ways both on fresh installs. I installed 7.2 personal edition straight out of the box and downloaded the drivers from Nvidia following their intructions. I get OpenGL support in my games no problem...but my GL screensavers and Blender both look for Mesa drivers. I also tried getting the software update from the Yast Control Center before I installed the Nvidia drivers from Nvidia....I get the same bugginess before and after I install the Nvidia drivers from Nvidia's site.
I did what it said and mine works fine on a very similar system to your own (V550, AMD450). Without the switch-file being run I got about 50fps in 'gears', afterwards I got over 400. (Just type "gears" in the console and that should run it - it prints the FPS in the console window so you can see if your 3D accel is working)
I ran gears and I get a little more than 600 FPS. Brian D.