Dell laptop cannot change resolution

Hi all,

XFree 4.2.1, Mandrake 9.0, Dell Inspiron 8000 w/flat panel 1400x1050 refuses
to show anything on screen except in 1400x1050 resolution. I tweaked modes &
v/h rates, and X will now even go into 640x480 mode just nothing shows up on
the screen - it's black. That hi-res mode is hard on eyes, and I need to be
able to run 3D games in lower resolutions as well.

I've seen people mention their laptop screens were able to change
resolutions fine in 4.2.0, should I just recompile other X server version?
If so, which one?

Peter