Migration Assistant not seeing Active Directory user accounts

I have a lab of Leopard Macs that are bound to our AD. I would like to migrate each users' home folder from their old Leopard Mac to their new Lion Mac. The problem is that Migration Assistant only sees the local accounts on each old Mac and not the AD accounts. Each users' home folder is physically there locally but MA doesn't see them so I'm unable to migrate them.

Any tips on how to get this working? Thanks