They replaced the phone because it is a known defect at Palm.

Others will want to keep this in mind however. If you purchase the phone used, even if it is still well within it's warranty period, Palm will require you to pay for the repair. They claim the warranty is void if you are any other than the original purchaser. This is clearly a design flaw that has affected many people. Palm should replace/repair the phones affected as an attempt to protect their brand's reputation. It's sad that they don't.