A couple possible reasons:
1. Your broker or a company that you work with needs to send the information to Trulia about the property. It isn't a given that it will be on the site (someone correct me if I'm wrong here). I am pretty sure that you can also manually enter it or get it on here through another site, but I have never had to do that so I really don't know how.
2. As with any database search. If your parameters are too specific, you may miss your mark for one reason or another (EG: "Street" instead of "ST"). Try to be more general in your search and see what you come up with maybe just specify the city and the price to see if it comes up in the list.
From what I can tell, this listing information simply hasn't been submitted to us. Please access the link below to review your options to submit the information to us. If you only need to submit a few listings to us, we recommend that you use Single Listing Submit. You will need to manually enter the listing information, however the listing will be live on our site within approximately 36 hours. Click on this link to get started: http://www.trulia.com/agent_login/?r=submit_listings/enter/