I don't do much sewing of garments, but I do buy the Threads magazines. This morning while sitting around I picked up the Nov. 2006 issue and there was an article about doing shoulder adjustments. From my limited knowledge

, it looks like your problem was being addressed when they were diagnosing fitting problems for square shoulders. Maybe this helps....
"Square Shoulders
A relatively high shoulder point scoots the armscye up, leaving the shoulder seam and neckline unsupported. Thus, the neckline stands away from the neck or horizontal wrinkles form across the upper torso in front or back."
"For Square Shoulders, Angle Up
Square shoulders need a seam that slants less steeply from the neck to the shoulder point than it does on the pattern piece."