Offline Files not working when connected to network with different domain

This is a problem that has been bugging me for ages - We use offline files within Windows 7 so that staff can access various network shares when not connected to our school network. This works fine, and when staff work from home or out and about, the shares are available and so they have access to their docs and various desktop and start menu redirects without a problem.

However, if they connect to a network with a different domain controller available (i.e. another school), the offline files are not available. We have lots of staff going out to different schools, and the only work around is to disable all network connection until they have logged on. That way they can have access to the offline shares as well as have network access. If they don't do this, then their docs, desktop and start menu don't load correctly and the laptop is unusable.

Anybody come across this or have any ideas for a solution?

Windows should ignore different domains, unless it's confused because they have the same name. What are the errors, event log items etc?