nail pops on walls are like nail pops on treads of stairs. They are protruding out due to out ward forces. Shifting walls due to foundation movement and a bowed tread on the stairs.
When this happens, the nail hole is usually compromised and nothing will hold that nail SECURELY again.
Nail hole pops on ceilings can be readily fixed for a short term by hammering the nail again into the drywall making a concave dimple of sorts. then you can appy drywall mud or spackling to that dimple and paint over that. Do not make the dimple so deep that it breaks the wall paper. Now, this will eventually pop out again unless you sent the nail in further to find new wood, but your chances are slim.
Here is what I would do: dimple the nail in the wall as above. then one to two inches below and above the nail, screw a one and a half inch or longer drywall screw into the rock and then into the stud. Lightly over screw the head so that it also dimples the wall but NOT TO BREAK THE PAPER. spackle this again and this area will not cause you problems again.