Just posting to confirm poster's claim: OF iPhone crashes constantly (on sync attempt) for me too.
System: Latest SneakyPeek, 1.0.3 iphone app, syncing via mobile me. Pretty big dbase (yeah, I know that's vague; don't have time to learn how to find size right now. over 1000 items total)
Fix attempt: rebuilt OF dbase on mac, deleted dbase on phone, reconnected & re-sync'd.
Result of deleting & resyncing was that instead of OF iP crashing while attempting to open and sync, it would (eventually) load and be accessible.
But... I would then add a single item from the iPhone app (with just a title; no other info), go to the OF iP home screen, then touch the "sync" button in OF iP. Spinning gear icon would spin for 20 secs or so, then app would crash out to the home screen.
I just quit using OF iP for now. :-(