Well I'd hate to suggest something idiotic but is the right wiper blade tightened down all the way?
Also if that doesnt work pop off the wiper and see if the stud turns when you run the wipers. If it turns then it's probably just a problem with your wiper arm which isn't a biggie it's good to replace those things every once in awhile anyway. (Original from 16+ years ago... probably not good).
If this stud doesnt turn then there is a linkage problem but I dont believe that is the case if you saw it trying to move.
Other than that I'd need more details hopefully that will get you started.