Hi gizmo350,
There may be reasons why the user has not responded yet, even if that sounds ridiculous. Sometimes, a non-responsive buyer suddenly re-surfaces. I've had that happen to me. Everything checked out smoothly in the end. Just took a little longer.
Follow-up with eBay by reporting the non-payment. Close up all venues with this eBayer before re-listing or doing a second chance offer.
I'm only saying this because it seems less stressful this way. My own experience.
Fester