Achievements Glitch

I don’t mind that this happened but I earned two achievements from the Noble 1 map pack, but I never bought the map pack. I got the double kill with a shot gun achievement one day when I was playing zombies By myself even though I’ve gotten plenty of shot gun double kills before.

I also got the achievement from killing someone in a rocket hog race match, and I have done that plenty of times before.

I’m just wondering, has this happened to anyone else; getting a map pack achievement even though you don’t own the map pack?

Also, do you have to own the map pack to get the achievement? Or can you still earn it without buying it?

Because for other achievements I try to get that are Noble 1, I can not unlock them; like the cross mapin one, even though I’m across the map in a big team game and I kill someone with the dmr, or a sniper.

Hey I have had the exact same thing happen to me for the Defiant Map Pack. I’m guessing it’s probably something to do with the TU that changed something since I started getting them after.

I got the double kill with the shotgun achievement on 9/25/11, so that was before the TU. I then got the other one on 9/5/11.

Oh ok then I have no idea because I started getting them after.

I got the double kill shotgun and crackin skullz one. ( no map packs purchased ).