I have to say, since the upgrade to LEM 5.6 and the new database, getting results for more than a week or two in the past is next to impossible. I just tried searching for an event for the past month and a half, and the graph got about halfway through populating before Time Out occurred. And even though the graph (and listing on the left) said that there were over 800 results, the Results Details pane says No Matching Results.
I'm really hoping that the next update fixes this; otherwise this product has become almost useless.