It is a fairly common problem in breeding. Once the snake has gone a few days without depositing more eggs, but more can be felt inside her, you must intervene as soon as possible.
I describe aspirating eggs in my Cornsnake Manual, but if you are a beginner breeder you should probably seek help either from a very experienced breeder or a qualified, experienced herp vet. Maybe your local herp society can help you find one or both.
As for the future, my own "gut" feeling (no scientific evidence though) is that the incidence of egg binding is partially determined by genetics (some bloodlines are more prone to it than others)and also by lack of exercise and muscle tone. That part can be improved by larger cages and/or letting the snake crawl around (and climb, too) as often as possible throughout the year.
Be sure to take care of this problem soon - once the eggs solidify, they can no longer be aspirated and may require surgery.
Good luck!