Take it back, try a different disk.
If this was a problem it would of shown up weeks ago if it was a genuine issue with all players of the game that have put the hours in over the last month, almost 2 months now...
We have two copies in the house and me and my son have not had random lock-ups.
If it locking up in the same place time and time again then some more info would go along way so we can try to help and for Larian Studios once they get a chance to read this topic, but with not much to go on then we can only guess.
Other wise try a new disc.
