Hi Ken:
How are you doing? Sounds like you're experiencing similar frustrations to what I'm facing. From what I've been able to discover, the SQL 2008 Spatial FDO provider does not support SQL Views that are made by joining tables in SQL and it does not support Feature Joins created in Studio on SQL data connections.
I've updated the Autodesk SQL 2008 Spatial FDO provider with the latest OSGEO release. It solved some other issues with SQL 2008 data (namely MGE not recognizing UniqueIdentifier data types), but still no luck on the joins.
Here's an OSGEO post that might provide some clues. I haven't had time to go through it entirely yet, but I'm hoping that we may be able to come up with a workaround from some of this info. http://n2.nabble.com/SQL-Server-2008-views-and-fdo-again-td4273589.html#a4295305
At present, what we are doing is creating a new table that joins data from the required tables in SQL Server, creating a stored procedure that updates the new table on a regular basis (almost live) and then using that table in MGE.
Let me know if you come up with any solutions.
George Gaeke
Global CADD Systems Inc.