I did post a thread on the official forums:
http://forums.bistudio.com/showthread.php?190983-SetPos-amp-amp-attachTo-loop
Bascially when you do a setPos loop (in this case to make two fences moving apart), it doesn't work as intended in a dedicated environment. Its somewhat laggy seems like the pos update takes too much time to complete.
So is it related to the net sync?
Render time scope?
Loop is too fast? (I also tried increasing the sleep time) {F26153} {F26154}