I've always had subtle sync issuse across my Cats since 3.3. Of course things have gotten better but the jump from 3.3 to 4.01 on my 10.3.x machine showed small gain and less jumpiness.
When I would run 4.01 on 10.4.6, it almost seemed worse. Today I tested 4.0.6 m66UB on 10.4.6 (clean install of everything, drives zeroed, content fresh). I am still having sync issues. Sharing is off and only network connections are Cat machines and switch.
Normally it wouldn't matter but because I'm using edge blending and my files are exactly side by side, I have the hard line that shows the jitter. I'm been through both forums forever on this trying to find solutions.

Here's a thought though, since I need Audio on some of my files, I would assume just have another media server to run audio only. Isn't this what SAMSC is for? The big question, is if there is DMX control for SAMSC? Since I'm the one running the audio cues, I need to be the one running the audio from my lighting console. What do you suggest? What is the most reliable sync option for Catalyst layers (to give me the best looking playback)? Why I'm at it, what is the best TimeCode Generation software or hardware I can get to timecode my shows?