title: .isproj cannot be opened because of its project type (.isproj) is not supported
body: <p>I've got 2 VS 2008 based solutions I'm opening up and both have projects that are .NET 3.5.  But when I open both solutions in VS 2008, both have some .isproj file(s) and I get this stupid error right after I open the solution:</p>
  
  <p>c:....\somefilename.isproj cannot be opened because its project type (.isproj) is not supported by this version of the application.</p>
  
  <p>When I open the .isproj I see that the project version appears to be VS 2008:</p>
  
  <p>9.0.30729</p>
  
  <p>So I do not understand why I'd still be getting this error and I have never even seen or at least had an error with a file of extension .isproj in any of my apps before.  I guess it is used for MS Build?</p>