Installed BlueSMiRF Gold on Arduino Uno via prototype shield. All connections corrected and tested. I can see, and pair with, BlueSMiRF Gold (FireFlyxxxx) from laptop, and BlueSMiRF Gold red LED flashes as if waiting, but BlueSMiRF Gold never connects; green LED never lights. Have had many successes with many Arduino plus XBee components using this computer, but upgraded recently to OS 10.9. After fussing with BlueSMiRF Gold, via Arduino Serial Monitor and CoolTerm, using USB and Bluetooth, changing baud rates and trying various connection options, I still only see modem-incoming, never modem-outgoing - confirms that BlueSMiRF Gold never properly connects. Worse, after switching cables to wireless and back, Arduino software will not load. Re-installed Arduino once, which worked, but still fails to load after any tests on BlueSMiRF Gold. Computer re-start fixes the problem. Other Arduino sketches and functions seem to work. Something weird about BlueSMiRF Gold and OS 10.9, Bluetooth and 10.9, or about OS 10.9 and Arduino?