Update: Take a look at this bug report. There is a kernel patch (at comment #5) that corrects the problem described in this post. Per the latest update, this patch is now in cvs, and will be released with the next kernel update!
I just wanted to note that if anyone is having a problem with the ASUS K8V SE Deluxe motherboard (DMA timeouts), add the following options to the kernel boot line:
# grub.conf generated by anaconda
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/md2
# initrd /initrd-version.img
title Fedora Core (2.6.8-1.521)
kernel /vmlinuz-2.6.8-1.521 ro root=/dev/md2 noapic pci=usepirqmask
This solved my problems. It looks like there are some problems with the IRQ handling in the current (1004) BIOS.