On my (short) experience TGUI96xx is a very unlucky choice for linux.
I had a lot of problem with it and as far as I know from people answering
to my question on the group I'm in good company.
Anyway you can re-program the modeline in XF86Config either runnig
XF86Setup or editing them directly in the XF86Config, which sould be
in /etc/ or somewere else (find / -name XF86Config). If you want to
try to edit the modelines by your self try to read
the XFree Video timing HOWTO
Last suggestion. If you run XF86SETUP you may have problems trying with
1024x748 resolution that stop the 800x600 to sync up. Just remove from the
> I want my card to have 85hz refresh rate like is possible in NT 4.0. It
> currently is set to 40.000 hz refresh I think because i noticed "Mode
> "800x600":mode clock = 40.00 when I shut down X. How in God's name do I
> change it so it uses 85hz (highest possibel refresh with my card) so I
> don't get as much flicker and so its easier on my eyes?