Paul, I believe it is simply a gravity and weight problem. With what you are using the only fix I can come up with is storing the binders either laying flat or with the three rings facing up so the pages are hanging down with the weight evenly distributed on the three rings. I use the binders from Cheques in the Mail, Inc. They are expensive but the pages do not sag and retain their shape nicely, not to mention they are great looking. I know this is not much help,others may have a better solution.