Bluesmirf Arduino Uno trouble

Hello, I am trying to set up a serial connection between an arduino uno and a mac pro laptop using a bluesmirf gold. After successfully pairing the device with my computer I have still not been able to establish the serial connection. When I try to upload arduino using the firefly tty serial port, it says serial port already in use. any advice? Note: all other applications are closed and i have restarted the computer yet the error still occurs.

So are you actually trying to upload a sketch to the Arduino Uno via Bluetooth instead of USB connection?