Customer reports problems ordering from iphone

I just had a customer call and cancel the order that she made yesterday because she didn't think it went through so she ordered from another site. She was using an iphone to place the order and she said when she completed the ordering process, she was returned to an empty cart page instead of a confirmation page. As a result, she thought the order failed and so she went to another site and ordered the same product. Later, she checked her email to discover that the order did, in fact, go through. I don't have an iphone to test this problem, but I was wondering if anyone else has experienced similar issues.