Midi Fighter Spectra and OSX Problems

Hi all. I am having an issue with my Midi Fighter Spectra and 15-inch Macbook Pro (OSX 10.8.3), and I'm hoping some of you can help me. This is what's happening:

If I have my Midi Fighter plugged into my Macbook, and I am not running any programs that receive MIDI (e.g., Ableton, Logic, the MF Utility), I get a delayed response from the LED rings whenever I hit a button. More specifically, every time I press a button, it takes about a second for the ring to light up. Here is a very short clip illustrating the problem:



Once I open a program that receives MIDI, the problem goes away, and the Midi Fighter begins behaving normally. I get the same problem on my wife's 13-inch Macbook Pro (OSX 10.8.3), but not on my PC (Windows 7). Have any of you experienced this issue? If any of you decide to try it out, I would greatly appreciate it if you could post your results as well as what OS you are running. Many thanks!