I have installed knoppix 3.2 6-6-2003 version on my hard disk. I have a 19" monitor and my knoppix display occupies only part of it. And the rest is just black. I get the whole display properly except that it is not occupying my monitor's viewable area. It happens only on X display. When I ctrl+Alt+F1/2/3... it is fine. I get the whole screen. How can I tell the X-server that I have a 19" display and not a smaller one as it thinks? Is there any setting that I need to change??

Thanks in advance,
Sanjay.