People! Just read the posts before you post... All those values are refresh rate values (60, 75, 85). The new drivers seem to default to vsync enabled on TNT2 cards.
Try "__GL_SYNC_TO_VBLANK=0 glxgears" and see for yourselves (I did and I went from 85 to 235... yay!).
If it works (it should), just add "export __GL_SYNC_TO_VBLANK=0" to some initialization script (/etc/bashrc, .bashrc, .bash_profile or whatever).
Downgrading... people just like the easiest solutions.