Micro,
Sun, cards do wear out and go bad. That happened to mine. - It's a brand new card.
Likely power. - it requires a 500 watt power supply - I was running a 600 watt, and when it kept shutting down, I ordered and replaced it with a new 750 watt power supply just in case that was the issue. I think that original issue was in the adapter from Molex to 8-pin.
So I would at least hope that it's not a power issue.
ArVee - it's a Galaxy rather than an EVGA - I'm thinking maybe talk with Newegg and see if I can't replace it with an EVGA? Have you seen or read about any issues with the 660's?
Below is the error log - looks like she did a restart at 22:41 - and the last entry on the regular log is 23:07 - not sure how long she does run before doing the restart.
*********************** Log Started 2013-01-16T22:41:29Z ***********************
22:44:01:WARNING:WU00:FS01 : Detected clock skew (1 mins 09 secs), adjusting time estimates
22:45:09:WARNING:WU01:FS00 : Detected clock skew (1 mins 25 secs), adjusting time estimates