You have several answers and none are quite accurate to my understanding. First, Trulia is not connected to Northwest Multiple Listing Services, our local MLS that all licensed brokers in this market uses. To appear in Trulia a local broker may load it individually or syndicate it through a number of sources. I upload my listings to Postlets.com which in turn sends them to Trulia, Zillow and many other sites so that my listings have the greatest possible exposure.
If your previous broker loaded it up, but your current broker hasn't replaced it, the old information will stick around a while. You can suggest your new agent load it directly or syndicate it through their office or by other means.
Some homes appear here that are not for sale. This data is pulled from county records and may not be up to date. I hope this helps.
Please notice where the data DOES NOT COME FROM....the local MLS.
A study completed at the start of this year reveal that 30% of the data appearing on aggregate websites is FALSE.
Your current agent will be able to address this for you. Let your agent know. Be aware, serious buyers use serious resources such as the MLS. What appears on aggregate websites is quite irrelevant along with the evaluations, guestimates and values they display.