Everything would have worked for you, like survivalpenguin said. The FF license wasn't compatible with the debian license, so they re-branded everything for distribution. Same nuts and bolts tho.
Common problem with alot of linux distros. Run "lspci" and/or "lsusb" to discover your BT device and use that model # for search terns on the mint forums. 99% chance that should square you away.
Ya edit the sources.list or use the gui? I live behind the bash shell at work. 1. backup sources Code: sudo cp /ect/apt/sources.list /ect/apt/sources.list.old 2. edit sources, using gedit. I use nano, but since you are in the gui already, we'll use gedit for this example. Code: sudo gedit /ect/apt/sources.list add your apt line in there and comment out anything you don't wish to use. 3. update sources Code: sudo apt-get update 4. upgrade packages, assuming your upate went smooth Code: sudo apt-get upgrade -y /end