this post on Edelweiss Patterns blog explains why the pattern is so tricky and gives a tutorial on how to fix that. According to Katrina's post, the pattern companies don't regrade the original vintage patterns, but make "adjustments" for the modern woman (she got this tidbit from a McCall's pattern maker). So the tip is to choose the pattern size by your collarbone measurement and grade the rest of the pattern out.
It may sound a bit funny, but it really works! The blog post explains everything and has pictures (thank goodness!). Be sure to see her second dress attempt for an even cuter version! Also, she is toying with the idea of a sew-along for this pattern, so if you are interested please visit the second version post and leave a message.