This is an old issue, actually. If you try to connect to a game and someone launches it while you are in the "connect" phase, this can happen. I believe i requested SD strike games like this, but can't remember off the top of my head. Anyway, I have seen this sort of thing in the past, but it really only happens as I've described.. now if you are saying you weren't even logged into DG and didn't try to join that game (even for a moment), the I'd say something else is up..
There have been some behind the scenes things I've worked with SD on re: stats in the last few months that should improve things. I swear this was something I've mentioned at least...
