Originally posted by GotPhotos
yeah sometimes you have to hit the dashboard on xbox, or reset your console, or sometimes even reset both your internet connections...try those things first...
They update the playlists and it isn't the same as having to download an update that is applied like a patch, they do it while you are playing and some people have the new playlist, and some have the old.....so you have to sync back up with the new one so to speak (so I am told) I am outta my league here, just trying to give you an idea of what the problem might be.
This is exactly it. Restarting your game should do the trick. Small updates(patches) can be given to the community uknowingly, so when you log into online you recieve it. I believe we first saw it in w@w.
Another possibility-Some people cannot join each other. But usually if you could join an hour before, then this is not the case. If the first option doesn't work, then you might just have to find a third person to invite you both, because as of now I have not found a fix to the second one.
Hope I helped