I'm not sure if this has anything to do with me being on WordPress 3.3 or not, but I don't seem to be able to use the plugin.
Once I click on the "thumbnails" link under an image, I get the Thickbox window popup, where I can see in the background the image and all the image sizes under it. But this window remains greyed-out, with that animated loading bar running over it - and that's how it stays forever. I close the window, try again, same thing. I just can't get the loading bar to disappear and allow me to actually access the editor's steps.
Any feedback, suggestions, help would be hugely grateful - as this plugin is EXACTLY what I've been searching for!