I picked up an HG20, but I'm having an issue with it. Even though I set it to AV output (vs headphones output) in the menu, when I switch it to recording on the mode wheel, the headphones icon appears on the screen. When I plug in an external microphone, the "Off mic" icon appears on the screen next to the headphones icon.

Any ideas what to do?

Did you set it to AV when the camcorder was in recording mode (not playback mode)? I know it sounds odd but I noticed the reverse; I had set the output to AV on playback (so that it would play on the loudspeaker) but when I switched the camera back to record, it put the output back to headphones (and kept it that way when I again switched it back to playback). So it seems the camera only remembers the setting one way...

Regards
David