Trulia has missed your purchase entirely. There was a sale on March 11th, 2003 for $498,000 and your purchase of $855,000 on 4/20/05 simply never got into their system. Sadly, this is an automated system and sometimes they just don't pick things up.
I hope someone in admin notices this and corrects it for you. But not to worry...if you are planning to sell your home, a real agent will see your purchase and use that data correctly.