Evolution freezes on calendar page

[Matthew Saltzman]

Suddenly, whenever I switch evolution to the calendar page (or whenever
it starts on the calendar page) it locks up.  The status bar shows
several occurrences of attempts to sync a couple of calendars that I
subscribe to in gmail.  

The last act I completed successfully was to create a recurring
appointment in my Exchange calendar.  The first lockup occurred when I
tried to copy and past that item (though I'm not sure there's a causal
relationship).  (Probably should have just created the next appointment
from scratch, rather than trying to modify a copy.)

Also, the Google calendars that are shown syncing are not my own, but
ones I subscribed to.  They don't have passwords associated with them,
but I keep getting popups in GNOME Shell asking for those passwords.

Any idea how I can at least get around the freeze in order to retry
things?  I can't use Evo to unsubscribe from any calendars because one
does that from the calendar screen and the calendar screen freezes.  Is
there a config file that I can edit?

Also, how can I get GNOME to stop pestering me for the nonexistent
password?

TIA.
-- 
Matthew Saltzman
Clemson University Math Sciences
mjs AT clemson DOT edu