Description of problem:

If you create a booking and immediately create the similar booking again (the email and the amount of the tickets may differ), the checkout of this "second" booking causes that two bookings are save in the database.

Version-Release number of selected component (if applicable):

WFK2 ER6
EAP6 ER8

How reproducible:

Always.

Steps to Reproduce:

1. build and deploy Ticket Monster
2. click on 'Book tickets' button
3. select a venue Roy Thomson Hall
4. click on 'Order tickets' button
5. choose a section D - General
6. provide a number of tickets you want to book, say 1
7. press 'Add tickets' button
8. insert an email
9. press 'Checkout' button
10. click on 'Bookings' menu item to see, that your booking is there
11. repeat all the steps above again
      - you can provide different ticket number and email

Actual results:

There are three bookings (assuming that no booking was there before step 1.).

Expected results:

Only two bookings should be there.