Oh thank god! My duck was doing the exact same thing. I have been stalking the internet, worried about my female india runner. Everything I could find said vent gleet, prolapse, egg binding . . . None of it seemed quite right. She has been healthy and happy, just . . . leaking. Not the awful smelly stuff discribed (waaarf!) in the hen/chicken forums, and nothing resembling a shellless or broken inside of her egg, but instead an odorless, and clear.
She is 22 weeks old, and has yet to lay her first egg, so there is still plenty of time for me to panic and think things are wrong, but at least some discharge is normal. This is my first time raising duck friends, and I have got to say, they are a lot more fun than chickens! haha