I'm having the exact same problem. It only started happening after the move to Grey Havens, so I suspect it's an issue with the servers. The problem is, like you say, about every three seconds it freezes up, and when not frozen, the rubberbanding makes the game essentially unplayable. I spend more time looking at a glitched or frozen screen than not.

I've told people about it in-game, and some of them are also having this problem. However, certain people, including those in Europe, do not. Is there a fix for this? Or do we have to wait for GH to patch it?