Originally Posted by defaultdotxbe
AFAIK there is no glitch from the DLC, i got all the achievements with DLC weapons enabled no problem
The guide writer noted them as glitchy but didn't really expand on that. I was assuming that the DLC gave you a level higher tier weapon than normally achievable, (like the origional Godfather) and once enabled you were no longer able to upgrade weapons further nullifying the achievement.
I was about to play it through twice, 1st without DLC gear second with DLC gear on Nightmare but now I don't have to. I will play once to enjoy the experience, then cheese the rest of the 1000. Some games I work for, but this one isn't it. I got it to try it out on a whim Its cool, but 2 playthroughs would be too much for this type of game for me. I still have Deus Ex to get done before the next few games on my Gamefly hit release day need to go fast!
EDIT: I have the Weapon/Dress DLC and all achievements popped no problem, including last checkpoint on Nightmare exploit. Not sure if that was an issue but extra confirmation that it works fine.