I have a Dell Latitude D610 with the Intel 915 video and a 1400x1050 LCD screen.

Using the Knoppix 5.0.1 CD, I used the following line:

knoppix dma screen=1280x1024 vsync=60 xmodule=i810

1280x1024 is perfectly usable. I haven't tried 1400x1050 yet, but I don't think that will work without using the 915 video patch. Maybe this can be added to the next version of Knoppix as a cheat code.