Might want to head over to the Mac forums for more detailed help on your problem -- but BB's don't sync with mac's without a 3rd party program (no DM for us ), and there isn't exactly a good fix for that either. best option atm (in my opinion) is bootcamp'ing with XP.
EDIT** lol, you'll notice that the first thread is MISSING SYNC SUCKS!!.. that's the state of bb+mac at the moment =\
im using a windows now...when i plug it in it syncs to the computer for like 3 seconds and then disconnects...
my apologies for the misunderstanding on my end then. I would still recommend the Mac forum for some more help. to throw out a random fix all -- try a battery pull and then connect it again.