Bumping this back up as the same issue is apparent on Fedora Core 1.
Botond's suggestion works for Fedora aswell:
try this in your /etc/modules.conf file and the ...0261 network driver will work fine:
options nvnet optimization=1
(I had the same problem you described above, but now a 2.4.23-rc5 kernel works smoothly with A7N266-VM).
For other valid options see the README file on the driver's page.
Strangely I have the exact same motherboard aswell!
UPDATE: For me, this option gives frequent hard-lockups requiring a hard reset. I usually cannot get back into Fedora as bootup usually locks. Be very careful if you try this!