I'm having serious network-related problem when playing Spiral Knights. Certain aspects of the games suddenly stops working for long periods of time, and it happens constantly. Despite the problems persisting over fifteen minutes the game does never actually disconnect. The game works fine on other networks, so I know it's not my computer.

I have 10mbps download, 0.7mbps upload, and three or two bars of ping in-game.

I have tried port forwarding (47624 through 47634) and setting up a DMZ.

What doesn't work:

* The game does not load new areas. If I enter the elevator or try to move to another area of Haven my knight will simply stop moving indefinitely and no loading screen pops up. This is, of course, the major issue.
* The chat does not work at all. Messages I or anyone else write does not pop up.
* When talking to NPCs or interacting with objects, my knight performs the appropriate animation, but nothing else happens, i.e. no shop window opens when I talk to shopkeeps etc.
* The mail inbox does not load.
* When in the clockworks the UI for health and items does not update, i.e. when I pick up an item it does not display but I can still use it.
* When hitting enemies the damage is not displayed, even though it's enabled.
* There is no "strike flash" animation when hitting enemies.

What does work:

* Characters and animations in general. I can see other players move about their business (though I can't interact other than walk around them in circles). Enemies behave normally and my own knight can walk around and hit stuff just fine. Gates, boxes and other stuff in the clockworks remain in function.
* Some parts of the UI. I can get to the menu and log out or quit (but not return to haven). "News" in the spiral uplink loads fine. I can fiddle around with my equipment and items.
* I can pick up items.