Mobile Users is a new feature of 10.3. It basically synchronizes user, workgroup, and computer records when the mobile client connects to the network. It is specifically LACKING (Apple-supported) synchronizing between local home directory and network home directory. When a mobile user logs in, a brand new local home directory will be created for them (unless one already exists, which might cause problems!) If all your users use the EXACT SAME computer each time, I suggest you explore moving your server to 10.3, making all your users mobile users, and implementing a manual synchronization upon login and logout. I’d be awful nervous about the synchronization falling apart at a crucial moment