I need to use the Live Trace in Adobe Illustrator to prepare some images for more work in Photoshop.

I've completed jwebster45206's 2D Comic tutorials which were very helpful, but seems I've missed a setting somewhere with Live Trace.

When I use Live Trace, it traces completely around the image, even when it's a thick line. Ideally I need a thick line to have a single path traced inside it so that I can then add stroke thickness and other effects to it.

I've been looking for the solution for a while and have not been able to find it. Guidance would be appreciated.

Thanks