Project GUID keeps changing

Question

We have a VS2008 solution and i\'ve noticed something weird happening:

some projects refer other projects that are defined in the same solution (added as project ref

Answer 1

The problem for me turned out to be a duplicate GUID in one of the solution files. Inside the .sln for my installer I found that the Config project GUID (used all over the place) and the Installer project GUID (specific to the solution) were identitical. Opening the solution caused VS to change the GUID for one of them in the project file, though not apparently in the solution file. As it happens it always chose the shared one causing maximum grief. The fix was to create a new GUID for the installer project, and manually edit all the other solution files back to the correct GUID for the Config project.

I've no idea how this came about since I don't ever copy projects to create them.