Payment Address is held in the listing itself. This is by design, so you can have different payment addresses for different items.

You probably can use the Bulk Edit tool to update all your listings to your new Paypal email. You may need to customise.

http://pages.ebay.com/sellerinformation/video/BEAR.html

You MUST also update all templates, and be careful of any old item that you relist.

The easiest solution is to leave your old email address in Paypal just in case.