I just noticed that if I leave the game logged in but minimised in the background, then maximise it to try and play, everyone on screen looks like they just that second stopped moving, and the "Receiving" number is in the high 3000's or low 4000's before taking a nosedive. So this issue only happens... when I'm actually LOOKING at the game.

Great.

(Would also like to note that I have tried all the stuff suggested in the Error Code 2002 thread, port forwarding and all.)