I missed the fact that the attachment point is adjustable. From the picture (which doesn't give a totally clear view) it looks like the attachment point is a bit high on your shoulder - maybe an inch? If I have the option, I usually move mine to a point just forward of my shoulder, but not quite on top of my collar bone.

Like I said, I'm not sure I'd mess with it if the pack fits comfortably; this would be a tweak to try if you end up with a pressure point just below your collarbone, in the shoulder area.