What do you trying to backup? I enable todo/calender/contacts/task, and they sync well. But crashed when backup is enabled. I think the backup backup things in the system and that is why it crashes. O/w you can specifically specify the sync item and it should be fine. Please report back whether that is the case, at least that is how I use sync. Stay away from backup.

Edit: Is your last apps attempt to write to the card? I found out any attempt to write to SD card by hotsync with crash the hotsync. Have NOT figure out a way around it. Yes, you can manually write to your SD card, but hotsync is "stubborn", I guess

bun