WSPR Shuts Down

Last 2 nights, WSPR has shut down around 1830z

Other times it goes through the night without a problem.

Using WSPR version 1.12_r1177. Win XP sp3.

Being sporadic makes it difficult to analyse what's going on.

The only other event on the computer at that time that I'm aware of is a scheduled scan from AVG anti virus. There's nothing in the AVG event log that indicates it has a problem with WSPR.

I won't be sitting up overnight to observe what happens, so I may never find out. :o\