We are having some performance issues with our EF4 MVC solution. We\'ve been able to track it down to ArithAbort getting set to off before all connections to the database, a
EF provides the ability to insert a Wrapping Provider between Entity Connection and SQL.Data.Client - see http://code.msdn.microsoft.com/EFProviderWrappers and http://blogs.msdn.com/b/jkowalski/archive/2009/06/11/tracing-and-caching-in-entity-framework-available-on-msdn-code-gallery.aspx
Now I admit this is more of a clue than an answer - but perhaps you can insert the relevant set at this point ?