The issue:
I was on a project in Adobe Flash that required the use of video. The Flash movie was 24 Frames Per Second (FPS) and the video 30 FPS. When played back (Control > Test Movie) the audio in the video turned out to be way out of sync.
The solution:
This may seem like a no-brainer, but in order to sync the video’s audio, both the Flash movie and the video need to be at the same FPS, in this case 30 FPS. I made this change in the Flash movie and bang!! Still employed.