OBJECTPARK SOFTWARE With our first 64bit version of MenuCalendarClock, we tripped on a bug in Apple's 64-bit Cocoa on 10.5.x. This problem does not occur on 10.6. It does not occur on Machines with "Core 1" processors. It also depends on the recurring events you have in iCal.
WORKAROUND: In order to work around this problem, please quit MenuCalendarClock from the "gears" popup menu. Then find the MenuCalendarClock application in the Finder (usually in the Applications folder), hit Cmd-I (or "Get Info"). Find and check the "Open in 32-bit mode" checkbox. Run MenuCalendarClock. This will not harm MCC's operation or performance.
We will issue an update ASAP to work around this bug automatically.
Dirk Theisen for Objectpark Software
(Version 4.1)