Hi Christopher,
Thanks for your info. Sorry you had an issue as well. Was your crackling sound like this? https://vimeo.com/31374644
I have suspected that it might have happened because I turned AGC on for the first time, but it had worked without incident for two days, then it happened on the third day of shooting.
I also think it might have been condensation, but if it was, it was a minimal amount of condensation inside the camera.
I haven’t been able to duplicate the issue, which is good and bad I guess. I still use the cam and it is working fine, until the next time it happens! But I have turned the AGC off.