dwater
>....large files stores in their 'My Documents' and > they must all be copied over from the server when > they log in.... (&)...log out.
Well, are you using Roamimg Profiles ?
If so, the users need to keep their locally stored files to a minimum, perhaps save them directly on a server ibay. Alternatively you could point the "My Documents" folder at a mapped ibay, and then that part is already done for them.