Wiper Problem on Saturn SC1

I have a Saturn SC1 Coupe, 1998 model, with 109,000 miles (and a bit). I have no idea what kind of engine it has, except I know it's not a V8.

My driver-side wiper became loose today while driving to work in the rain. It will wipe too far to the left--even run right off the windshield when I'm traveling at high speeds. And it won't return all the way down to its proper position; it stops partway down--right in my line of vision. Also, when I got out of the car to inspect it, I fiddled with the passenger-side wiper blade and found it firmly fixed in place, but I was free to move the driver's side blade back and forth across the windshield.

I know the motor and the main moving arm are good because the passenger-side wiper has no problems wiping; and it wipes at the proper speed, works on intermittent, stops when I turn it off etc; the driver-side wiper's erratic behavior is the only thing amiss with the whole system.

I had the same thing happen to my old Festiva, only in that case the body of the car had rusted out around the windshield wiper arm and gave it no support. That's not the case here because everything looks sound around the wiper arm and it's not loose/wiggly; it's just not locking itself into proper position. I'm hoping it's a loose screw somewhere in my wiper assembly?