The primary cause of the problem is actually chase. Assuming optimal internet and hardware(for flash rendering), there would be otherwise no delay. However, the server does not wait an appropriate amount of time for chase chain to resolve, instead considering it as almost instantaneous. This means that once a chase happens, players will fall behind the server state resulting in all sort of problems.

So no, it's not necessarily the player's problem (thou it CAN be, bad internet certainly doesn't help). There is, without a doubt, a server/game side problem.