In my solution explorer is SetupProject when I need make installation for program I select this project right mouse click and Build, this build each project. Some times I select solution and make Build.
Maybe I know where is the problem I have only one AssemblyInfo.cs file and reference it for all 9 project.
And when Builds first project Add-In change version first time, when Builds second time Add-In change version second time
and so nine times.