Offline files Sync

I have been using the offline files on my network for 2yrs with win 2000 on laptops with no problems syncing them with the server. I created a folder for each user that is called my documents. When they log off it looks for changes and syncs if necessary. I have been using win XP with new pc’s and for some reason the file sync keeps breaking and defaults back to documents and settings. If anybody has any ideas as to fix them let me know.

If i rebuild the pc it all work fine for a couple months then just stops working.