When the long awaited 'Ranger Pack' DLC was announced for http://www.trueachievements.com/game.aspx?gameid=2294
fans of the game were pleased to finally be offered a long awaited expansion to the game. Soon after, in preparation for the update, THQ released a title update as groundwork for the DLC, but in doing so inadvertently glitched many of the achievements added by the DLC.
THQ acknowledged the issue via their official Twitter feed
on August 3rd, but there is still no word on the problem being successfully eradicated, aside from the fact that the team is still working on it. A statement released to Joystiq explains further:
We understand some people are still experiencing issues with achievements unlocking in the Metro 2033 Ranger Pack DLC. We are currently working with Microsoft to ascertain whether this is due to a code related issue with the DLC itself, or an error in the Marketplace process whereby the DLC was added to Xbox LIVE Marketplace before the new achievement data was added - this exact issue has happened to other games in the past, but we need to be sure that this is what's happening here. We realize this is frustrating for those of you who have been waiting to enjoy the Ranger Pack DLC, and we ask for your patience as we try to pinpoint the exact issue and solution.
In short, they don't know where the problem lies yet, so haven't truly begun working upon a fix. If you haven't purchased the DLC yet but intend to, hold off until this scenario plays out and is fully resolved.