So, to save everyone a lot of time...
We recently moved up to 2010Q1 release from the 2009Q3 release. Initially, we encountered the problem described in this thread
that required us to remove the project reference to the OpenAccess.targets file. But that lead us to having our assemblies not enhanced by OA, and that lead to runtime issues.
The problem lies in this snippet from your project file - which has Telerik rely on MSBuild for enhancement tasks rather than the AddIn for VS.
<UserProperties OpenAccess_ConfigFile="App.config" OpenAccess_ConnectionId="DatabaseConnection1" OpenAccess_Enhancing="True" OpenAccess_UpdateDatabase="True" OpenAccess_EnhancementOutputLevel="3" OpenAccess_UseMSBuild="True" />
OpenAccess_UseMSBuild is evil with this purported "fix" for the linked-to transient field issue. You have been warned.