PHD’s – Dock not syncing

I’m having serious problems with portable home directories. Ideally our users should be able to move from computer to computer fairly easily – even if logging in and transferring their profile could take a while. However, certain preferences (most notably the dock) seem to reset when users log into new computers.

In an attempt to fix things, with one test account I have

Reset the sync settings to defaults through workgroup manager (by setting everything to never, applying, then back to always)
Deleted the home directory on the server
Made a new home directory through workgroup manager
Repaired permissions
Deleted the filesync databases
Deleted the contents of ~/Library/Byhost
Synced by logging out and in on a machine with a stored PHD
Made changes to the dock
Logged out

When logging into a differnt computer (after ensuring there is not an old, local version of the PHD) I get sync warnings for 7 or so plists (including dock, global preferences etc)

Any idea why there would be a sync conflict when there are presumably no files on the computer to conflict with?