Hi Mathew
I run my GPDX / SS2K combo off a 12VDC 2A regulated mains adapter and it has always worked okay so far. I guess you could try a re-set and then have to enter the Date, Time, Lat, Long, Time Zone again.
On the SS2K Yahoo Groups someone once had a problem where they could not connect and had to attempt it 20 or 30 times before it connected.
See message
http://tech.groups.yahoo.com/group/ss2k/message/969
Cheers
Dennis