I've solved it a couple more times.... The method that seems to work is to ignore the ones with no cables going to them. Connect the three on each "half" first. I then go to one of the two sides where you have two "lighted" nodes that are not connected. I put up an order bubble right in between them... then run to the other side as fast as I can and do the same there. I guess I'm somehow bridging the two sets of three, and connecting all six together?
Don't know, but I know it has worked every time I've tried it since I first solved it accidentally.
Good luck!