The dynamic texture and volumetric texture projects both have identical guids. Normally people probably won't notice (since the solution references projects by both name and guid), but tools like Incredibuild fail because they see several projects with the same guid. Project dependencies use the guid too, but luckily the 2 projects in question aren't the dependency of anything else (of course).
When vs.net projects are copied/pasted and renamed to make a new project rather than using the application wizard, you must edit the guid in the .vcproj file to be unique (I just change a random digit) before adding to the solution.
Well, you can edit the solution after adding the project, but it's more work that way (changing 6 guids instead of 1).
