I used to exclusively go after old listings. But I agree with Justin in that 99.97% of the time a listing has not sold is because it is overpriced. Either the agent "bought the listing" by promising some ridicules price, or a stubborn owner who put a couple grand in upgrades and expects to get double that back plus labor.
Bottom line, if the house was burned to the ground, infested, with 2 liens, but was worth $800,000 and would only take half of that to make all the problems go away... and the asking price was $1000..... it would be sold by nightfall.
You can blame the economy, market, neighborhood... doesn't matter. Lower any price on any property to the right price and it will sell. No need to do any more digging. With these properties it is all numbers. I used to make offers on all of them unseen at 50% or more less than asking. I didn't do any research until I got a call back or a signed offer.
Now I am not suggesting anyone do this. Just saying it works. Whenever I got a price ridiculously low, it almost never matters what the actual property looks like or where it is. So there is no answer to your question of "what's wrong with it? Why isn't it selling". Lower the price and we have a deal.