Lag issues - HELP???

Since the announcement of the crimson DLC, ive been experiencing really bad lag in halo 4 mathmaking.

Not only do players jump around the screen (aswelll as myself, half the time i have nfi how i got to a particular place) but it also goes to the starting game screen, showing bpoth team rosters while the game still ontinues, im stuck at that scrren (i can tell because the scores are still going up)

I have the content from disc 2 installed.

Pls help, matchmaking is atm unplayable and its really annoying!!!