Odd problem with player position

I have added an RPG weapon to my game using the crossbow script. It is really weird but when I select the RPG when in 3rd person the player only holds it with one arm and the animation shows this, I don't want this, I want him to hold it with both arms like he does with every other weapon. Also now when I change back to other weapons he is still only holding them with one hand.

Any suggestions? Thanks