I noticed it was taking awhile to unlock the achievements. I think there may be a lag in the system. I think it may only update after "round" of play has been finished and it has checked back in with the cloud to confirm.
~Leonoux
I have cloud disabled, like I do for all my games, even though I still stay online. Honestly, I can't remember why. So, for DE:HR we have to have steamcloud enabled?