trckrunrmike, there could be several things gone wrong. Maybe it's not fermenting yet. If that's the case, you might have a very high Sugar:Water ratio. Also, it may help to activate the yeast in warm(er) water when you initially mix it in. Also, I've heard that you MUST use de-chloronated water for the mixture, otherwise the yeast will not live.
When I first started with DIY my biggest problem was getting a good seal between the tubing and the bottle cap. Try this experiment: plug the exit opening of the airline tubing with your thumb, and squeeze the bottle with your other hand. If there is air (co2) escaping somewhere, you have a leak! That would definitely end up in no bubbles.
HTH, keep us posted! 8)