I have the same thing, at least I think so. It's not so much an audiable clicking, but I feel a "click" in my right foot everytime the right pedal gets about 3/4 from upper-vertical. I've noticed that if I back pedal and come forward again, it doesn't do it. If I pedal with just my left foot, it doesn't do it.

No front derailer, so I'll check my chainrings and the pedal today.

Thanks! Let us know if you figure it out!

Vincent