Stretched screen on Dell Latitude D820 with GeForce 7300??

I have a brand new Dell Latitude D820, with an nVidia Quadro NVS 110M / GeForce Go 7300 graphics card in it. When I boot into Knoppix (v5.1.1, Jan 4 2007 release), the screen is stretched (the LCD on the laptop is 15.4" widescreen), and I need the screen to not stretch, but to display at the desired resolution.

When using the cheat code screen=1280x800 or screen=1920x1200 (with "knoppix " preceding, of course) (and both of these should be supported resolutions), the screen resolution upon loading fluxbox (my WM of choice) seems to revert always back to 1024x768, stretched.

The nv driver loads fine upon boot (at least, it seems to). I tried the boot cheatcode "xmodule=nv" along with the above screen cheatcodes, but to no avail.

I am up for remastering the CD if needs be, to include the proper driver, but I'm not sure where to get this or if I will have to recompile anything ...

Does anyone know how I can effect the desired screen resolution, not stretched??

Best,

Fred