This error has to do with the XFree86 config file. I'm not sure about Mandrake, but in Windows it's at /etc/X11/XF86Config or /etc/X11/XF86Config-4

This file can be hand-edited or configured via a program such as Xconfigurator or xf86config (I think those are the names of the programs? if you have them installed)

What video card are you using? If you're using an Nvidia based card, go to the Linux section of nvidia.com and there is a detailed text file with everything you need to know about this file to get it to work.

theres a way to have xfree try to auto config itself you type "XFree86 -configure"

this will put the autodetected conf file in your home dir

after it does this it tells you the command to type to test it out. i think its like "XFree86 -XF86Config XF86Config.new" while in your home directory, but it will tell you when you do it.

if that doesnt work post your video card specs and your XF86Config.

yes...that's what u get with mandrake. All those wizards are not so smart after all