Thank you for helping bartosh, but last night I finally got it working!
<img src="https://dl.dropbox.com/u/21499454/events.png" border="0" />
Using this, and also having tons of bullets being fired, I was able to get around 2000+ FPS!
In this screenshot I had recreated the lines you had and zoomed out to see who was targetting who, which reduced the framerate a bit:
<img src="https://dl.dropbox.com/u/21499454/framrate.png" border="0" />
The targets update every 500ms, as I heard the 'Pick closest' was very CPU intensive, which is why it seems they aren't aiming at the closest enemy in the screenshot.
Thank you so much for helping me get this work, and have an awesome day! :)