Izzdan, I'll be happy to play with you using my special sync tracking build. I need someone who can recreate it consistantly.
I was personally playing for about 8 hours today with people to try and nail it down but in that entire time we were unable to make it happen. And these were all megagames with 8-10 people and all sorts of units and crazy things happening.
To be honest, we haven't personally seen a sync bug in over 6 months of regular gameplay and methodical testing but due to reports like yours we believe one still exists.
Shoot me an email at email@example.com or meet me on the Sins IRC channel so we can arrange a game with my special settings. I would love to play with you so we can find this once and for all.
If there is anyone else who consistantly gets sync bugs, feel free to get a hold of me too. The more data we get the better.