Didn't have this issue from 5.0.12 but now after a period of non activity in RC5, I get an error when trying to connect to my shares over the windows network. As long as I maintain some sort of network traffic, the machine stays on but after a random period of inactivity, the machine seems to shutoff the network adapter.
I used SoftPerfect Network Scanner to see if it was just asleep and if I could send a wake up on lan packet to it but the ip is gone. Using 5.0 rc5 w/ the 8168 driver currently but I've also tried the regular rc5.
Edit: 8/24/2012 - Decided to swap out network card (Fry's card VT6130 based) for a Trendnet RT8169 card. After two days of usage, it's back to normal.
syslog.txt