Just today I was able to complete the whole campaign on Veteran, and did not get the "Black Ops Master" Achievement. I even have the other "Veteran" achievements to prove for it. I know the first thing people will suggest is that I haven't completed the two missions "U.S.D.D." and "Revelations" on Veteran (as they are non-combat missions), but I can reassure you I have. I have even tried redoing the final mission on Veteran just incase you had to complete the final mission last for the achievement to generate, but still not luck. I'll add that I completed all missions on Veteran while playing offline, but that really shouldn't make a difference in whether I get the achievement or not.
So just wondering, has anyone else had this problem, and if so, were you able to find a solution?