Windows 7 User in Mac OS X 10.6 Environment – Account Becomes Disabled

I have a Windows 7 user (my boss, incidentally) who logs on to my Mac OS X 10.6 file server with credentials from Open Directory. He might be able to connect once or twice, but then the account becomes locked and I have to go Permit Login again. He has started using a local account on the server in order to log in, but the folder hierarchy of the sharepoints are complicated, and permissions are very precise, which means that the local account doesn't have access to some of the files he needs. Has anyone run into similar issues? I'd like to be able to fix his current account rather than try to recreate it and give it the same UID, etc. Thanks much, _josh