PHD vs. iPhoto?

Hi all, I'm trying to figure out why iPhoto keeps throwing sync errors on our 10.6 PHD accounts? I currently have the ~/Pictures folder set to sync at login and logout and to never sync in the background. Each time the user logs in they get an error "There is a problem syncing the file "iPhoto Library" " I've read other threads about users having this issue but haven't seen a solution to it. Anyone have any suggestions?