Mac syncing has been problematic from day 1. PocketMac is good for older Macs, but newer ones, like anything with an Intel chip, often gag on PocketMac. Mark/Space's Missing Sync
helps some folks who have zero luck with PocketMac but even Missing Sync fails for lots of people. Entourage is the best syncing solution for Macs (with either PM or Missing Sync) in terms of reliability and ease of syncing, but it's far from ideal.
The best bet is to wait for the September release of the BlackBerry Desktop Software for Mac from RIM. It's the Mac users' unicorn, having been rumored, spied in testing, and dreamed about for years. Now we're finally getting it for real.