I'd been puzzled why all of a sudden, my widgets would stop working - I couldn't, when going to the widget area, move them around or anything. Also, when I had the google calendar plugin installed, upon setting up the wp-greet program, not only would the widgets not work, the tool tips on the calendar(s) wouldn't either.
I finally narrowed it down - it's the wp-greet program that's the culprit. I removed the google calendar plugins, and it happened again, so if you want to use widgets with the weaver II theme, do NOT use the wp-greet plugin - there's some kind of incompatibility issue. If someone else has found this, let me know, or is it just me?