Problems getting resolution right on Dell Latitude D810

I have a Dell Latitude D810 laptop, and I'm running Knoppix 5.0. It has an ATI video card, Chipset ATI Radeon Mobility X300 (M22) 5460 (PCIE), it uses the ATI_driv driver. I know it can run at 1600x1200 at 32 bit in windows. But when I'm running knoppix it won't autodetect resolutions that high. I've tried manually editing xorg.conf, removing mode lines, adding them to the screen section, and replacing all the xorg configs I can find on the system, but it will still start up x without the higher resolutions. I did however break it once by changing the horizontal sync and vert sync in the xorg.conf . I've been looking on the internet trying to find the correct hz and vert sync rates for the screen, but I can't find them. So basically, my questions are, which xorg.conf should I edit, and what all should I be editing? Is there an example out there that I should try? I've also tried using the boot code to force it to 1600x1200 but that doesn't work either. My next question, how do I get it to keep that setting after rebooting? Does the save knoppix confiuration from the kde menu cover the x configuration? Thanks in advance. If you want to see my xorg.conf that is generated by knoppix let me know, I'm new to this whole forum thing, so I don't know how to attach it.