How can I reset front wipers on Peugeot 206?

Hope someone can help.

I have a Peugeot 206 and with the snow a few days ago one of the wipers was frozen, which I found out when I switched them on. The passenger side wiper started juddering until they were both free. They both work as normal but now they wont settle in the normal position when they are turned off.

For example they should rest at the bottom of the windscreen when they are not working but when I turn them off they jump back up to just below half way across the windscreen. How do I reset them so they stay in the normal position when they arent in use. ie bottom of the windscreen?

Thanks for any help

Paul
December 2010