mobile home synching, has a mind of it’s own.. or … WTF ?

I’ve had very odd experiences migrating local accounts to mobile accounts..

I generally do this :

bind the cpu
create the OD account, assign to a managed group that specs a mobile account ..
the user gets a server home dir specified, and I create these with only the folders I want to sync…

use nicl on the local machine to delete the users netinfo entry (working from an admin account)
change the home dir name if need be, and then chown the home dir to the new OD user name
slick,
when you then log in as the OD user, the local home directory is already there and the user is asked to sync..

the problem is with synching..

does anyone know exactly what happens here ??

sometimes it asks which to use local or network ?
obviously we choose local .. and the ENTIRE local home is copied to the server regardless of settings.

I set to sync only Library and Desktop at login-logout and even add the ~/whatevers to the skip list..
but it doesn’t seem to care at the first login

what I want, is to only sync several directories and have the local home be the "master" ..
I don’t want a users music, pictures, etc filling up my server..
I DO want them to be able to login to another machine and have their own "user experience" ; prefs and in-progress (which is on the desktop)

OK, so once done, I just delete the unwanted folders from the network homedir
BUT, at the next login or logout..
SOME machines want to continue re-copying the whole local homedir back to the network homedir.
(yes, all the folders in entered in the skip list, too)
even worse, some others, have trashed files from the local homedir ! (to match the network homedir ? but not all ..)
and there’s nothing to indicate this is happening or going to happen ..

It seems there is some point where some accounts are happy only syncing the prescribed folders to the network home and will leave it with only these folders. Some have been inconsistent at copying files FROM the network directory when the user logs into a new machine and sets up a mobile home for the first time (after the account has been in use).

thus I say WTF !!

can’t find docs on the managed prefs plist files, or exactly HOW the whole process is wired..
there’s obviously some hardwiring going on here ..
servers are at 10.4.6 (newer g5 xserves)
and clients are at 10.4.x , mostly 10.4.6)
all managed prefs are group level ..

so can anyone explain how this is SUPPOSED to work and how to get it to work the way I want it to !!