Freezing!

[Fiyablayze]

Argh!! The game has froze and made me turn my whole xbox off about 10 times today! I'm doing ' One Man Army' and I'm up to Gideon, but the game froze during saving of the twins and when I beat levels it says 'under' for all the stats/money etc but in the map it's normal... I'm doing the 'beat bosses only' thing, am I going to have to start again because of this? And how do I fix freezing permanently?!