You don't need xfree
This has nothing to do with the X configuration, x.org is simply the xfree you used in your last distro but with a few bugfixes. This is a kernelmodule that is not loaded, I have had this problem myself. To fix it you have to load the first or second mandrake disc, look for the rpm file that has got something to do with the kernel source, rpm -i install it. cd into /usr/src/linux/doc look for a document about agpgart and figure it out that way, it is not that hard, you only have to sit down and press some buttons for about 5 min. I had the exact same problem myself, and that is how I fixed it. You can also search the forums here, this question has most likely been asked earlier.