Asus Bios bug
I posted a while back about 2 A7N266-C (nforce 415D chipset) systems. One works perfectly with Redhat 7.3 (bios 1.001E) and the other with 1.03 hangs when you try to "startx". That post was called "Problems with A7N266-C" or something similar.
I finally got the guts to do a complete reinstall, but flashed to 1.001E. The system worked perfectly. Flash back to 1.03 (or 1.04) and startx locks the system. (Note, the nVidia drivers weren't even installed, they are not the issue here.) It appears all the Asus A7N266-C bios revisions that are newer than 1.001E break something and cause Redhat lockups. It appears to be APM related as far as I can tell. After a lot of work, a friend of mine was able to get Redhat to work under 1.04 by doing a LOT of hacking with the kernal to remove all APM support.
I'm sure this same problem affects A7N266-E and A7N266-VM users. Asus' bios is to blame. Something changed between the 1.001E and 1.03 versions related to APM causes lockups.
I'm considering writing Asus to see if they know about this issue.