I swapped the MSI K9N2G Neo (nothing worked right with that thing) with a ASUS M2N SLI Deluxe, and everything worked the first try (except the nvidia driver, but I just compiled that). I had to use an older beta driver to get it to work with an XFX Geforce 8500gt, but it is much faster than the old mobo with the onboard 8200. Now to install LMCE tonight and set that acpi boot option!
UPDATE - now both onboard NIC's don't work at all! The first one doesn't even light up for link, and the 2nd one appears to work, but it can't see anything. Some help is needed here, I think the problem is that eth0 it thinks is disabled, yet it is showing eth1 with the IP below in the tools, so it is trying to send out the wrong interface.
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.80.0 * 255.255.255.0 U 0 0 0 eth0
192.168.1.0 * 255.255.255.0 U 0 0 0 eth2
link-local * 255.255.0.0 U 1000 0 0 eth0
default 192.168.1.1 0.0.0.0 UG 100 0 0 eth2
Also as an aside, the acpi boot option disables USB mice on this board, so I didn't end up using it. I just turned off power management in the BIOS.