EDIT: the original problem has now been solved!

however, i am still having problems with opengl apps. glxgears shows that my opengl framerate has improved eightfold (!) but when i try and run some opengl apps, such as lincity-ng or graal online, all i get is a white screen, or some parts of the screen appear correctly but others don't. one app that does work is gltron, but it is temperamental, as sometimes i get segfaults and 'SDL Parachute Deployed'.

any ideas?

thanks in advance.