title: VS2008 project with Entity Framework model results in "always dirty" compile
body: <p>In VS 2008, I have a simple .csproj that contains an Entity Framework .edmx (V1) file.  Every time I build the project, the output DLL is updated, even though nothing has changed.  I have reproduced this in the simplest-possible project (containing one ordinary .cs file and one edmx model).  If I remove the edmx model and build repeatedly, the output assembly will not be touched.  If I add the edmx model and build repeatedly, the output assembly is modified each time.  This is a problem because the real project is a dependency of dozens of other projects and it is wreaking havoc with what times when working in higher layers of the application.  Is this a known problem?  Any way to fix it?</p>
  
  <p>Thanks!</p>