We all tend to point out issues with Microsoft Windows, but of late, Post launch of Leopard there have been all kinds of issues that seem to rise out of nowhere.
Applications, long running on the Mac under Tiger (OS 10) or Panther (OS 9) all of a sudden seemed to "break" for no reason. I experienced that with Counterpath's Eyebeam, Gizmo Project and SightSpeed, all of which fixed their issues within a very short time frame, but I continue to have issues with Mac Mail and my Exchange server in Exchange mode and Apple has only advised that the issue is now with Corporate Engineering, who last week had the week off for the holidays.
Now today a reader forwarded me an issue some users are having with iChat on Tiger. Sounds like somewhere Apple made some changes to the Kernal's that impact real time communications and authentication, and unfortunately, some users are severely impacted.
Getting Apple to even discuss bugs is impossible. You just have to wait for the fixes.