"Real" (not forced) AC in one of your docks. I suspect it's also happening in the car but can't verify because I don't have a laptop to read the serial.

The reason I looked into this was some stuttering/hiccups during playback that started happening since I upgraded Hijack (I think I was at v340 before.) I just flashed back to v340 and the messages disappear, so I suspect this might be related to something you've done between v340 and v344. Any ideas?