There was a MP-desync bug in previous game versions which the DEVS worked out. There have been some isolated desync reports since then, but there doesn't seem to be enough information to base an opinion on.
1. Which game version are you (and everyone else in the game) running?
2. What kind of hardware is each players using?
3. What kind of network setup is being used?
It is a rather big waste of everyone's time posting a thread such as this, with nothing else to go on...
the Monk