Function "attach media" from library doesn't work

I would like to upload all my videos as .mov into the media library and attach them with the attach function. But when I click on the drop down to choose media, there is nothing to choose. To choose a gallery is not a problem. What am I doing’ wrong, or is this a bug?

Thanks for help.

http://ww.wp.xz.cn/extend/plugins/cool-video-gallery/