Autoscroll jumping to wrong part of page

Hi!
I was wondering if anyone else has the issue where when a client selects the time for a booking, the page scrolls down too far. So where the client should see the details of the appointment before confirming, it scrolls too far, and only the confirmation button is visible.
Please see:
http://pistachioppc.com/jousi-id/ajanvaraus/
Many thanks in advance!