I experienced the same problem with lack of contact between the wiper and the windscreed. I don't know if this was part of the problem, but the nut holding the wiper arm to the drive mechanism was loose. As a result the "grooves" on the wiper arm that connect with the "teeth" on the drive post were totally stripped.
Of course I didn't know that until the driver side wiper stopped during a rainstorm!. So - check the nut too!

I did Gerald's method with the dremel tool this past Spring and has been working great since.

Turn on your wipers, then turn off the ignition when they reach there top most position, fold the wipper back so it is not tuching the window and press down hard on the arm below the hindge so you bend it tward the window. This shuld do it, otherwise bye a new wipper arm.

Mark

There are two fixes for this very common problem.

The first fix is easy, but people find that it doesn't last too long. See this site for info: http://www.volvospeed.com/wiperarm.htm

A better and more effective fix involves filing a little bit of the wiper arm base at two spots. See the below pic for exactly where to do it. You can you a small metal file, or a Dremel tool.

Gerald C