Well, I’m having the same problem but aggravated. Everytime I play, the ping varies between 30~400 ms. Howeer, this isn’t the worst part: the game environment halts for a while, as if my client is awaiting a response from the server. It stays like that for a few seconds, and then everything is warped and resolved in less than a second, making me miss those seconds of fight.
Furthermore, I was able to soften this issue by defining a local dns server for my adapter, and apparently solved this until today. However, when playing today the game began, again, to halt frequently. As a Pyromancer, I am frequently caught freezed in place when casting a spell, that actually isn’t cast. Monsters sometimes halt, and then warp around as iI couldn’t see their movements in real time.
I have already tried nearly everything (won’t buy a new router only because of one game), and only the dns server thing seemed to affect this somehow.
EDIT: I have only latency lags, so far no hard processing-related lag. FPS keeps at the same levels all the time. From what it looks, those latency lags seem to happen during high load times (when there are more players online).