I'm not 100% certain about this but I have a sneaking suspicion that Audio Hijack Pro might be a bad app to have on your computer. I used to use AHP on my previous Macbook to increase the system volume (it was too low). After a few months of use, my left speaker was not functioning. On my new macbook, I've used Audio Hijack to record some Safari audio. When I imported the recorded file into Garageband and pressed play, the Macbook emitted a loud "pop" and the speakers were not working. I tried playing a song in iTunes but got the same "pop" and no sound. I restarted the computer and (thank goodness) everything got back to normal. But I repeated this whole procedure and had the same results. I've been scouting on forums to see if people have been facing similar issues with the program. From what I gather, it seems that quite a few AHP users have ended up with damaged speakers but no-one seems to have deduced that AHP may be the cause. I've removed AHP from my system and deleted all the recorded files. I'm not sure about this at all. I hope that some one has a better explanation for this. In the meantime, I'm staying away from that program.