@Tom: in your schematics (and apparently on your board) I see you're using electrolytic caps for AC decoupling. Doesn't it cause problems for you? I see that the cathode of the caps is biased to +1V, but on the anode the voltage can swing from -1 to +1. On the long term, shouldn't it cause damage and malfunction? I might be seriously overlooking something simple, though...
Ooops! Good catch! Yes, the caps are backwards. I haven't had any problems with the two units I deployed, but I should update the schematic.
Thanks,
Tom