Can't Sync to Google Account

[Agent687]

A friend picked up the EVO on launch day, from Radio Shack where they just handed it to her and offered no kind of walkthrough. I've been trying to hep her get used to the phone, and to Android (I've got an Incredible). There's one big problem, and I've searched the forums and can't seem to find an answer. When she tries to add her Google account (****@gmail.com) in Accounts & Sync, it accepts her account name and password, and says the login was successful. When she hits the "Next" button, it brings her back to the Add a Google Account screen, where the options are to "Create" and "Sign In". Repeated the process multiple times with the same results.

Is it just a matter of continuing to sign in until it works? Or would a hard reset help? Or, is a trip to the Sprint store in order? Thanks.