actually I remember when I was looking for a new monitor that the samsung T260hd does seem to have some pretty severe input lag, not unlike what Lemm is talking about. Not sure what causes it but it is a real thing, just never experienced it firsthand I guess.
I should point out that on a game like blackops the issue would compound because you would be battling both the input lag and the internet lag, which is probably why you even noticed this. If you were to play say the campaign it would likely be much less noticeable.