My clematis has only one vine that is continuing to grow up the string trellis that it is on. When I pruned it I cut it back to about twelve inches. It grew well after that with about 4 to 5 vines. It did bloom and actually still has some flowers on it. However, there is only vine that is continuing to grow extend itself up. The rest seem to have stopped at the flowers. The vine is growing quite well...probably a good five to eight feet. This one vine is not flowering though. I did see that the vine seems to keep having a pair of leaves and then the vine continues up between those pair of leaves, and repeats. Obviously, I would like all of it to continue growing and flowering. What do I do?

Here's a link to a pic of a bloom from my flickr photo pages if it helps to identify (color edited but essentially the same)

http://www.flickr.com/photos/29613367@N07/3550109271/

(I just realized it would probably be a good idea to have a pic of the plant full sized...will post later if it helps.)