I've been downloading daily builds from here: http://build.oxygene.sk/job/package-picard-win-daily/

Last night I upgraded from #36 (Dec 13) to #40 (Dec 27). Afterwards, Picard would not open. Updating to Build #41 (Dec 28) today didn't fix it. I reinstalled 1.2 and it behaved correctly. Updating to #41 again caused the same problem.

I find this error in picard.exe.log:

Traceback (most recent call last):
File "picard", line 42, in <module>
File "picard\tagger.pyo", line 49, in <module>
File "picard\acoustid.pyo", line 26, in <module>
File "picard\webservice.pyo", line 31, in <module>
File "urllib.pyo", line 26, in <module>
ImportError: No module named socket