Success! I upgraded from MT3.2b1 to MT3.2b2 in under a minute. ;-) This upgrade went much better and I have been able, finally, to rebuild my previously existing blogs (well, I haven't tested ALL of them, but I'll work on that tomorrow). Installing the new MediaManager (replacement for BookQueueToo) helped ease the transition. I'll report separately about that.

Hi Kate,
I saw in the MT3.2 Beta Blog where we were having the same issue regarding duplicate entries in the category and montly archive templates.
Just wanted to let you know that it has been corrected in the latest nightly build that's on the site. I installed mine and the duplicates are gone.
Take care!
Thanks for the "heads up", Carla! :-)