i am using suse 9.2 and my onboard NIC is a gigabit, everyhting worked sweet untill i upgraded to this motherboard, i have tried so many different things to correct my network lock up problem, but it never occured to me untill today - i am going to use a standard 100mbps ehternet card plugged into my PCI slot, i'll see how that works, and let you know.
I also found this problem on another forum, seems like we're not alone:
arstechnica