[badchad]

Quick update: This was a very odd situation. I finally determined (through numerous hard resets and a few hours) that my lockups were the result of a single appointment.

For some reason, if I used the default calendar in "week view", and attempted to use the D-pad to navigate through appointments, my device would freeze on the very same appointment. I have no idea why. I'm thinking that it may have been due to all the text listed in the "notes" area of the appointment (it was a seminar with a long meeting title).

I deleted it and my problems resolved *shrug*.