I have just viewed your gallery in IE11 and all 27 thumbnails on your gallery's thumbnail page displayed fine.
Looking at your gallery's code, I see no reason why all your images should not load correctly (and they did when I viewed your gallery).
Perhaps there was a temporary glitch with either your web server or your internet connection which resulted in your browser timing out whilst loading some images.
The only thing I would suggest is that you try upgrading your gallery from SimpleViewer v2.2.0 to the current version (v2.3.1) as many bugs have been fixed since v2.2.0. For a full list of changes, please see the Version History.
For details on how to get the latest version and how to upgrade existing galleries, please see the Upgrading SimpleViewer page.
SimpleViewer Support Team