halo 3 co-op campaign problem PLEASE HELP!!!

hey guys,
So I recently got halo 3 to play co-op with a few of my buddies and for some reason it wont let me play. Everytime we start the game from the campaign lobby it just kicks us back to the menu with a message saying “restarting campaign from last checkpoint”. If I leave the lobby the game loads fine for everyone. Btw I have a 30mb connection so it has nothing to do with a connection issue.

Now I was banned from earning exp in matchmaking for 2 weeks for boosting a few achievements, which I understand is wrong but that was over 3 weeks ago and my matchmaking has gone back to normal now. And I can’t imagine that would have affected playing co-op.

We have tried everything -

  1. I have deleted the update and saved game data and re updated
    and that didn’t work
  2. I have 2 copies of the game in perfect condition and neither
    are installed
  3. Tried playing with different guys and still nothing
  4. Hosted the lobby myself and had others host and still
    nothing
  5. Tried saving on various different devices for example
    Hard-drive, usb and cloud storage
  6. Also tried it on 2 xbox’s and still nothing

Has anybody else ever had this problem or heard of it?

I have no idea what to do now and I really need your help PLEASE.

I really want to get all the achievements in this game but I will never be able to get the annual achievement if I can’t get this fixed.

If anybody has a solution to this or any tips of things to try please reply here or message me on xbox live my gamertag is

  • P4PA SMURF X

Also is there anyway to delete my campaign data off the server?