A few weeks ago (Nov 6th to be precise), we released Billings 2.5.2 with some very minor tweaks for Leopard - and then we pulled it about one hour later. We realized that the auto-updater just didnt work on Leopard and from the download stats, we know some of you (probably on Tiger) have this mysterious 2.5.2 release.
This auto-updater bug turned out to be a real pesky bug. I mean real pesky. We did some digging and found that Sparkle (the auto-updater) works just fine on Leopard. It was just that it didnt work in Billings on Leopard. If we built Billings on Leopard for Leopard, it worked fine, but if we built it for Tiger on Leopard or for Tiger on Tiger, it just wouldnt work. Obviously we had some kind of conflict - but where the heck was it?
Anyways, to make a long story short, we finally found the conflict (one flipping declaration we made many years ago) and we now have a working updater on Leopard.