This thread:
iCal Calendars Disappearing from Menu tells you what I've been going through.
Why do you need Pacifist? After really poking around on the Tiger disc, I found the iCal install pkg. It installed iCal fine...unfortunately, my problem appears to be one of my calendars.
I deleted the calendar in question...everything was fine. I synced with my Palm. No problems. I recreated the calendar from scratch, synced with Palm. Corrupt again.
So, for the moment, I have stopped using Missing Sync, and started just using iSyncno problems so far...I wish iSync was decent enough to truly sync my calendars (especially putting them into proper categories and whatnot)...