Hi Philip, Can you press ctrl (Control) key and press F5. Have the control key pressed until the page completes reloading. This ensures you have the latest copy of all depending files.
Let us know if you still have the problem after this.
Please create a support ticket @ /support_contact.php and attach the form and provide any additional information that could help us resolve. Probably the data that you enter and/or screen shot of the form with data entered.