Right before checkout the ticket order, you have to provide an email. When you start typing, the browser offers you the values that have been previously used. Selecting such proposed value does not enable the 'Checkout' button.

1. build and deploy Ticket Monster
2. click on 'Book tickets' button
3. select a venue
4. click on 'Order tickets' button
5. choose a section
6. provide a number of tickets you want to book
7. press 'Add tickets' button
8. insert an email by selecting some proposed value

Actual results:

The 'Checkout' button remains disabled.

Expected results:

The 'Checkout' button is enabled.

Additional info:

This is not an issue if using google chrome 17.0.