X and Fluxbox :: xsetup Q

I cannot get DSL X to work right.
It works fine with full Knoppix.
Here is the deal as reported by Knoppix:
Xmodule = vesa
and it is a sisfb device.

Knoppix gives 1024x768. DSL the most I get 800x600.
I have tried booting with fb1024x768 and I get "out of range" error on my monitor.

DSL using xvesa is that the same as vesa? I have to boot DSL with vga=normal.

This is a newer computer.
Help pleeze...
TIA

original here.