Problems using media library

I’m having some issues trying to use this plugin. I’d like to add some retina images to my site, mainly the header image. Not one part of plugin seems to be working for me. In media library I DO have the retina column, but there are no buttons in it like I’ve seen in screenshots from the tutorials. Existing images have no buttons or icons in the retina column, but newly uploaded images have that yellow “!” triangle. In the new “Retina” page, new images go to the “issues” tab. Existing pictures are in the “all” tab, but hitting the “generate” button just says “please wait” for a second and then does nothing. I read to install the “enable media replace” plugin, so I have done that, but changed nothing. Any screenshots in tutorials don’t much the version I have. I have no “upload” button beside “generate”.

– Plugin version 1.2.0
– WP version 3.5.1

I’m not super familiar with WordPress, so I might be missing something simple. So, sorry if thats the case, but I can’t figure it out for the life of me. No idea what I am doing wrong. Any help is greatly appreciated.

http://ww.wp.xz.cn/extend/plugins/wp-retina-2x/