I have not heard much about this from the gaming outlets or a quick browse of the Bungie forums and I thought I would reach (pun intended) out to the CAG community and see if this has happened to anyone else. While playing the campaign I received an achievement that I wanted to learn more about so I hit the guide button. I went on to complete the mission and saved and quit my game. The next time I loaded up the game I was asked to setup my Spartan and given 5000 credits as if I were starting the campaign for the first time. I immediately froze thinking that my progress was gone and that I would have to start from scratch. The strange thing was that my multiplayer progression and armor pieces I had unlocked were still there. I went to the missions select screen and was only shown the first mission. I then went back and chose Resume Campaign and the game started up right where I left off the night before. I quit my game and went to the Internet in search of answers. I only found one post on some site which mentioned that the glitch would happen if you got an achievement in the campaign and hit the guide button to view it (which I had done). I have continued on the campaign and noticed that now on the mission select screen I can see all the missions, but missions 2-5 are locked as if I have not completed them. I don't mind going back and playing them again, but I am curious if once I finish the game if I will receive the achievements for completing the campaign.

So, has anyone else experienced this glitch?