Does this help article on their site help?
http://support.kioskproapp.com/knowledgebase/articles/310838
Is the iOS device upgraded to the latest version with the latest version of Kiosk Pro?
Does the problem occur in their demo here?
If you can send your document to me I’d be happy to see if there’s anything strange about your document that might be causing this. Could you send send me a personal message. (Click ‘private message’ here).