i have the same problem. seems though, for at least that session if i change the driver for the intel pci express root hub-340a that the errors stop, next reboot though and they are back. system seems to work fine.
i have the 10-20-09 intel bios installed and manually installed the inf chipset to all applicable devices. weird though that the inf installer wont "really" install. after running it and it reporting success, all the drivers were still microsoft branded.
anyhow, need a fix for this error 5x/second in my event viewer.
note i have Nvidia gtx295 cards in sli. from reading all other posts everyone else has ATI, so ATI people, you are not alone.