Oh thats a different story. Resoultions are configured in XConfig86.conf (or something similar). Can't reall help you if youre using some GUI utility for configuration, though. Search around for XConfig info; theres lots everywhere.
mmarkin's right, you need to manually or use a program to edit /etc/XF86Config(-4). If you edit it, just try adding "1600x1200" as a possible resolution. That usually works, assuming everything else is configured right.
Yeah, just be careful about it. Usually, forums help with this kind of stuff (glad to say I got it working pretty quickly though; didnt have to do much after the ATI config utility). Although a different distro, check out http://forums.gentoo.org.
Glxgears results are about 2400 fps but fgl_glxgears are lower than yours, if I remember correctly. This actually makes sense - glxgears is really biased/inaccurate and fgl_glxgears shows the power increase of teh 9700.