battlefield 3 crashes

[mamba1071]

.i have 2 xbox's,and 2 discs.the game crashes on both xbox's with both discs. as i said all other games work perfectly,it is just battlefield that crashes on all game modes now.It used to be only on metro.i have tried clearing the cache and uninstalling and then re-installing but to no avail,7 out of 10 games it crashes now,with disc error.can anyone help?