Expired Listing? Pending Listing? What's the deal?

I ran across an interesting home that had been on and off the market in the past few months. The yard sign was still out in front of the house as well as the lockbox on the door. Flyers were in the flyer box. There was no indication of whether the house was still available or not. I couldn't find the listing on ZipRealty.com and my agent couldn't see if this house was now pending or not. According to her, the house was not yet under contract, according to the MLS.

What to do?

I decided to ask the listing agent directly. Maybe the seller was going to relist the house at a lower (or higher price)... Either way, I wanted to find out. So I search on the web for the agent's name and find his contact information email him. About 2 minutes after the email, my email gets returned, saying that the user does not exist. If you are an agent and don't have a valid email address, how professional can you be? I then call his office to ask about the listing. They say they think it is pending, b/c it isn't active, but they don't know. Instead of asking the woman to check, I just decide to have my agent research this a little more.

Maybe the home is pending, but you would think that an agent would make sure his email address was correct on HIS website. Good work Prudential.