Could you please update your WPML plugin to the latest version 4.6.7 and add-ons to benefit from the latest bug fixes and improvements? This may not necessarily resolve your problem, however, in order to troubleshoot the issue best we need to work on the latest code available.
You can check the latest released versions under "My Account -> Downloads" on this site. Instructions to update can be found here: http://wpml.org/faq/install-wpml/
Remember to backup your database first before you proceed.
If the issue persists after an update, please provide details and screenshots.