I just got the new xbox so far I have positive opinions of it. The UI needs improvement but it runs as smooth as butter and Kinect and the controller are good.

I did have a problem with dead rising 3 though.

I started playing the game and I unlocked the 100 kills achievement and I also finished two other achievements. But it still says I only unlocked 2 achievements (it's not counting the 100 kill achievment). Under achievments it says I unlocked it but my profile says I didn't. I tried deleting my profile on the xbox one and I typed my email back it that didnt work. I am reinstalling the game now. Do I just have to wait until I unlock the 'kill 1,000 zombies'  achievment? Let me know

Anyone? lol

Still having the same problem. I unlocked the kill 1000 zombies but it still didn't unlock the kill 100 zombies. I started a cold boot and reinstalled the game. anything else to try?

Are you playing in Nightmare Mode?

nope. I believe Im playing on casual. My mom happened to say casual when she was in the room when i was on the menue and it started without me doing anything. the game is pretty difficult so its possible i am though lol why?

Uhh, I don't know. Nightmare mode doesn't mean there's a casual mode. You can either choose the Story mode or the Nightmare mode.

*Maybe* if you're playing on Nightmare mode, achievements only unlock once you have beaten the game.

That can't be it I'm unlocking other achievments. This same thing happened to me playing gears of war 2 then I deleted my profile off my console and signed in again and it showed. Didn't work this time though

try here:
http://www.xbox360achievements.org/forum/forumdisplay.php?f=3164

I use the ps version of the site and they have an answer for everything.