TOPIC: Back button during grp reg causes problem.

We're in the final testing of our DT Register page before we launch.
So far it's the best event registration extension we've found!

However, there's one problem I can't figure out.

If you start a group registration, say with 3 people, enter all the information for each registration (tickets), and then come to the BILLING information page, hitting the "back" button on this page, goes back to a 4th ticket.

For example, here are the steps:
1. Go to event page and click "Register"
2. Choose group and enter "3" people in your group.
3. Enter the information for your ticket, click next. Repeat until you reach
4. Billing information. Click "BACK"
5. Notice that the system is asking information for registration #4.

Additional: If you click back again, it takes you to ticket #3 and then "Next" properly takes you forward to Billing Info again.

Any ideas?