a7n8x works like a champ with fedora (and rh9) here.
it is a little picky with memory dimms so.
had to replace 2 sticks of 512mb infineon ddr400 with samsung and
its 100% stable now.
an extensive forum for the nforce and linux is located here
http://www.nforcershq.com/forum/viewforum.php?f=29
best
lars