I've done extensive testing with many variables and have narrowed down my problem to common variables.
When I stream to a Wowza Server via Wirecast 5 (using churchstreaming.tv) with latest updates and all.... I have sync issues when using x264 encoding.
Avg bit: 1200
Target: 128 kbits/s
When I use x264 settings: the audio leads EVERY TIME!
It doesn't matter: I've changed systems - Mac, PC, different networks......
When I change the settings back to H264:
The audio and video is in sync.