jQuery Call Error: Session Variables not available on adding tickets

This is such a great plugin but I’m getting a jQuery Call Error: Session Variables not available every time someone goes to add their first tickets – after page refresh it’s fine. I tried using the no JQuery option in the settings but then the seat selection doesn’t work.

I tried forcing a refresh the first time the page is loaded but this doesn’t help as the Session Variable isn’t set until the ticket is added.

Happy to use a work around , just don’t want to have to add text asking people to refresh the page and start again if they get the error…

The page I need help with: [log in to see the link]