Sims keep freezing every cuple of minutes

I play on xbox and own all of the packs, kits ect... I am becoming incredibly annoyed at how everytime I play, my sims are literally freezing mid task every cuple of minutes, the only way to solve this is to reload the game, then after 2 minutes of play they freeze all over again. This has been an ongoing issue scince the marketplace update. My game has been unplayable for what feels like months now so I am not happy in the slightest, I would like this rectified ASAP as I have spent a lot of money on this game. Any help would be appreciated, thanks.