If you are getting mismatched DLL's or manifest issues after upgrading then you are simply linking with old dlls. Here's what you need to do.

1. Open all of your projects
2. Remove all EntitySpaces references
3. Close the projects
   
4. Uninstall EntitySpaces
5. Search for on your entire drive all entityspaces dlls and delete them
6. Reinstall EntitySpaces
7. Readd the references by BROWSING ONLY to our specific install folders (if you add from recent lists you will get old versions)
   

and it will work.

Visual studio moves your dlls all over the place, and if you adding them via tabs and not browsing to the specific dll you have no idea what you're linking to, for instance these two folders on your machine I can guarantee have all kinds of version of EntitySpaces dlls, Visual Studio is terrible about moving dlls everywhere.

C:\Documents and Settings\{username}\My Documents\Visual Studio 2005\Projects 

C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files