… make sure that you have removed all dependencies on the project that you are about to remove before you remove the project from the solution.

If you don’t, the projects that still have dependencies on the project you just removed will retain the dependencies, but the dependencies will have become invisible and the only way to rid yourself of the “phantom dependencies” is by editing the actual vxcproj files with a text editor and remove the dependency entry in there manually.

Don’t ask how long it took me to figure that out.