Knoppix and Screen Resolution

[nnigam]

My laptop which displays upto 1600 x 1200 with no problem under XP comes up as 1024 x 768 in knoppix. When I change the screen resolution in control center | display, I can go upto 1600 x 1200, howerver the screen comes up tiled instead of stretched to fill the screen resolution. Any idea on what I am doing wrong, and what I can do to get it to stretch to fill the screen. I would prefer a 1280 x 1024 resolution. I remember that in debian you can cycle through the available resolutions using some control alt +/- combination. Either I have forgotten what it is or it is not working in knoppix. Also, the laptop does not have a dedicated + key which may also be the cause.

Thanks
Neeraj