The PMC was unlocked earlier this morning, for ~20min, presumably from the rocks next door.  I relocked it.

Then, a few min ago, the PMC suddenly decided that it wouldn't lock with a transmission greater than ~0.7 .  I found that the laser temp adjust on the FSS screen was at -1.9ish.  I put it back to zero, and now the PMC locks happily again.  I think we got into a PSL mode-hopping temperature region on accident.