My friend and I have been playing this game straight for the past few days and just last night encountered a problem when we tried offline free mode. We both joined, but only the person who got the killing blow received experience for the mob. This isn't a problem in campaign mode, just OFFLINE FREE MODE. Really frustrating please help!
Also, I have already tried inviting him to my party, but this section is greyed out in offline free mode.
Also, we are using one gold account and one silver account on xbox 360.