If Project.ParentProject(string) is called, the project is not set as a child project of the project which was defined in the argument.
If Project.ParentProject(string) is called, the project is not set as a child project of the project which was defined in the argument.
An issue was addressed in the API where the function call was ignored. Now a project can be move to be a child project by calling Project.ParentProject(string). The first argument is the name of the project which should be the parent project.