It appears that SGU1 went offline at midnight UTC (4:00 pm Monday 9 Dec 2013.)
While it was tracking satellites, it was not computing a positions, delivering corrections or storing static data.
It was rebooted this morning at 9:45 am (Tuesday 10 December 2013) and appears to be working. (It was last rebooted July 1st 2012.) I don't know what was up.
I will keep close watch on it for a while. Let me know if you encounter any issues.
Mark Silver, firstname.lastname@example.org, 801-412-0011 x16