Those with long-standing birthday events in BusyMac's BusyCal [1] will appreciate version 1.1.2, which now calculates birthdays before 1940 correctly when running in 32-bit mode. That's obscure, as is changing the Decade date range in List View to 2001-2010, but more welcome are fixes for crashing bugs that could bite when resizing events in the Week view, if an edit and conflict occurred at the same time, and if a calendar didn't have a name. Also improved is BusyCal's handling of deleted Google calendar feeds. ($40 new, free update, 6 MB)
[1]: http://www.busymac.com/