Comor did that for me when I had that same problem. They also threw in some of the eliminators that the guy above was talking about. They kinda worked, but it never completely solved the problem. Just gotta try a bunch of stuff, usually the shop that sold the boots to you will be willing to help out a lot.
Oh, and this might seem obvious, but have you got custom footbeds? They keep the foot a bit more snug in my boots than they used to be. Those superfeet things.
Skiing's rad, hating's bad.