Yes, that's what it's supposed to do. The Product ID changes, depending on which option to choose in Tools > USB Type. Of course, it only shows up as a serial device after you've programmed it with one of the options with "Serial". The others don't implement Serial, so MacOS won't detect them as serial ports or modems.
Please email me directly about the DOA board, paul at pjrc dot com. Please include a link to this thread in your email, and info about the purchase (eg, order number or other info we can use the look up the order).