Find a bigger reason to let go off it. Put the relationship first. Start your own family book club, with parents, grandparents and children taking monthly turns choosing books. It's a great way to build children's reading skills, a chance to cuddle close when you're together, and something to talk about over the phone. Long-distance grandparents can even audiotape themselves reading stories.
Family relationships involve reciprocity, giving when it's needed.
A grandparent can gracefully agree to babysit in an emergency. Parents can make sure grandparents get thank-you notes for gifts they've sent so that they feel appreciated. Building good will helps everyone over the long run and sets a positive model for children. Post a message on the Community Forums.