Motorola Droid :: Invalid Username Or Password (Unlocking)

My first Droid had problems with basic applications such as the Messaging and Phone apps resetting, so I exchanged it. Everything seemed great with the new phone, until I woke up one morning to see a screen stating that too many incorrect patterns had been attempted, and I should reset the phone by entering my Google account information. However, upon entering my information, I immediately received a message "Invalid username or password." There was no apparent attempt to even validate the information. Anyhow, I returned to the Verizon store and after the representative researched for half an hour or so, he decided to factory reset the phone. Now, this would not have been a problem, except that I purposely entered an incorrect pattern five times afterwards, to get to the "Forgot pattern" screen, and as I had suspected, it refused to accept my information. I was wondering whether this would be valid grounds to exchange my phone once again. I'm not content with having to completely erase everything on my device each time my phone gets into somebody else's hands.