Alara

Still have the problem, using a Telstra Bigpond Pre-paid Dongle connected through a laptop via ethernet. Can play every other game under the sun without lag, cleared cache, you name it I've done it. Had it at my parents place, played it wireless over their connection no problems. Seriously, its frustrating!

Weird thing is, I can see my friends playing, and see their rank, but not my own rank and I can't access matchmaking.

Same. Haven't been able to get into Reach or Halo 3.