I tried the Bluetooth USB Module, Sparkfun SKU: WRL-00150 with a computer running Arch Linux that already had a working internal bluetooth module, and was unable to get it working. hciconfig showed the device, and running sudo hciconfig hci0 up brought the device up, and showed a valid bluetooth address, but trying to scan and connect produced no results. We tried this on two computers, and tried for a while to get it working. When trying a D-Link DBT120 which was bought as a replacement it worked instantly. Just so people know…