So I wasn't planning on posting but my problem is a little different then the other problems I have been reading about for the past 9hrs trying to get my core audio to work again...so here's the problem. Firstly: I have figured out that it has nothing to do with an update. It also does not have to do with any issues with the headphone jack. The issue is...that when I try to use any program connected to core audio the program freezes, and the only way to quit it is by doing a force quit. Also, oddly enough...when I use Ableton Live (DAW) the sound comes through the internal laptop speakers, but cannot be adjusted in any way, and the program does not freeze. The problem is almost that the audio is frozen in one position and will not change. I have tried editting the com.apple.audio.coreaudiod.plist file by changing the KeepAlive to true...this did not help. I have done a SMC, HW, PRAM reset. I have repaired permissions and also repaired disk. I have tried uninstalling programs that may be causing it without any success. I have also deleted my cache and preferences. Also audio is not greyed out like has been mentioned with other peoples audio problems The odd part around this whole problem is that the audio was working this morning, and after I restarted my computer, the audio doesn't work, because it freezes everything connected to it, which in turn doesn't allow the audio to play. When trying to access the Audio/MIDI setup, Audio/MIDI setup freezes and will not allow me to change any of the preferences. My internal speakers are still showing up in my system preferences, and everything seem to be running fine...aside from the fact that any application needing audio freezes, including iTunes, and i cannot use any coreaudio on my system. Any help would be immensly appreciated as this problem has been extremely frustating, and I plan to call Apple in the morning (unfortunately their help line is not available on Sunday's) My system came installed with Lion 10.7 (Currently 10.7.3), I have since followed all the upgrades with no issues. It is running an SSD with all my applications and another internal in place of the optical as a backup drive. 8gb ram, AMD Radeon HD 6750m 1024mb. ***if someone has a solution feel free to email me or post here...firstname.lastname@example.org ***I have exams on wednesday and it would be great if this shiny piece of metal would work for me.