Security Violation - imageblock External

I would like to show my photos at Nucleus CMS but following urls throw Security Violation Error

http://fotky.zvestov.cz/main.php?g2_view=imageblock.External
http://fotky.zvestov.cz/main.php?g2_view=imageblock.External

If I am logged I see

Error (ERROR_BAD_PARAMETER) : /home/zvestov.cz/web/ftp/web/fotky/modules/imageblock/module.inc
in modules/core/classes/helpers/GalleryPluginHelper_simple.class at line 94 (GalleryCoreApi::error)
in modules/core/classes/helpers/GalleryPluginHelper_simple.class at line 88 (GalleryPluginHelper_simple::loadPlugin)
in modules/core/classes/GalleryCoreApi.class at line 209 (GalleryPluginHelper_simple::loadPlugin)
in modules/core/classes/GalleryView.class at line 153 (GalleryCoreApi::loadPlugin)
in main.php at line 318 (GalleryView::loadView)
in main.php at line 94
in main.php at line 83

PHP Version 5.2.0-8+etch1
Gallery 2.2.4