Hi there, just installed your plugin, but when I test it I'm only getting old posts in the results, none of my recent stuff. You can try it out if you like: http://gatewaygazette.ca/search/ - we post stuff pretty much every hour, every day - so there's no reason for the top results in almost any search to be several months, or worse years, old.
Also, is there any chance you're working on a feature that will add the date to each of the post results.
And I'm sorry, but it's really annoying when you click on a result and then hit your back arrow on the browser to go back to the results and they are no longer there.
One more thing, if I may just offer the suggestion, it would be nice if the results were spread out just a wee bit more (larger space divider between each result) or even adding a divider line.
Having said all this - well done and thank you for taking the time to build a plugin for the rest of us, it is appreciated.