Samsung Zeal / Alias 2 SCH-U750

So my phone froze after receiving several text messages at one time. I turned it off (even took out the battery) and rebooted. When it came back up, it asked me for a password. I never set a password for the phone, and I've tried every number I can think of (last four digits of number, last four digits of ss#, and an entire assortment of other guesses). Verizon store said they couldn't help, and I would have to buy a new phone. Any ideas what the password might be? Or an override ability for the password? Thanks for all of your ideas.