Tony,
Make sure when CommCare HQ prompts you to copy over the application to your new space that you use only lowercase letters (even if the new project space name in the orange dropdown menu has a capitalized letter in it). Additionally if there is a space in the original name of the project space where you want the app to go, make sure to use a dash "-" instead.
For instance, if a project in the orange drop down menu is called "Demo Project" I would write "demo-project" when prompted to indicate where I want to put the copy of the application.
If this doesn't work definitely report a bug!
Cheers,
Claire