When multiple databases are involved, handling relations between them becomes a bother. Telerik OpenAccess ORM (as well as any other ORM) can only handle classes that are mapped to tables in a single database. However there is a simple workaround, you can always implement a custom membership provider that utilizes OpenAccess, this way you can have a single database that handles both your users and application logic.
I hope this helps.
the Telerik team
Q3’11 of Telerik OpenAccess ORM is available for download. Register for the What's New in Data Tools webinar to see what's new and get a chance to WIN A FREE LICENSE!