Hey guys! I found a bug in Reach!
A friend and I played some Campaign and then two games of Firefight. I got the weekly, but he didn't, so I signed out while he played Score Attack. At the end of the game he needed four headshots, so I signed back in and we went into Doubles FF. He got his four kills but not the credits, so we checked, and his challenges had been reset - but his rank progress and credits earned hadn't. I checked mine, and they hadn't been reset - I still had all five.
So I signed out to post about it here while he played some Gruntpocalypse to catch up again. And his challenges were back to before we'd played the game together, without his four kills. He got them and both challenges popped.
Has anyone ever come across this? I have my profile on the hard drive, an he has his on a memory card. When it prompted us for a save location, we both chose the hard drive on every session. When I signed in after his first solo FF run, we had a short period where it struggled to sync with the server and displayed us both as Recruits, but it quickly resolved itself and I've seen this happen before without any adverse effects.