Visual Studio Deployment Projects do not like dashes in your path.

I was attempting to build one of our projects under a new path and was experiencing this incredibly frustrating problem of having my output msi files being significantly smaller than the official build. We build a number of solutions and some contain Visual Studio Deployment projects which create merge modules. If I built the solution under c:\projects\WidgetX it built fine. If I built it under c:\projects\WidgetX-mirror it was missing a number of third party dependencies. Even pulling dependencies from the wrong location. It turns out if I remove the dash and build in c:\projects-WidgetXmirror it correctly detects dependencies. Underscores also work. Very bizarre.