Incorrectly detecting content location as inside installation folder

With Open Rails installed to "D:\Open Rails", and the Zig Zag Route content installed to "D:\Open Rails Train Simulator - ZZ", attempting to add the Zig Zag Route content to the installation profile gives an error with "Cannot use content from any folder which lies inside the Open Rails folder D:\Open Rails". The content is not within the Open Rails folder, but it does begin with the same string representation as the Open Rails folder.