Here's a video that shows how to use the automatic threader.
http://www.youtube.com/watch?v=ZFtMRE1DWDA
Sometimes the little wire hook that comes through the eye of the needle gets bent and then doesn't come through the eye, just right beside it, and then of course the needle doesn't end up threaded. If you play with it a little, you'll get the hang it. It's so much easier than the squint and poke method!