Sorry to hear that. for me working fine and i have WP 3.4.2 too. maybe its clashing with some other plugin? I noticed that i have to switch Minify in W3 cache if you using this plugin? Minify actually clash with few plugins. So better switch it off. anyway i don’t have many plugins (under 10) and running Simplo theme and works fine. Hope this can help you. Cheers
Minify is definitely a problem. Having CDN also seems to cause problems.
Basically… caching programs in general seem to cause a cascade of issues with this popup and I still can’t get it to work right without a lot of effort. For example – if I just use plain HTML or the wysywyg, it almost never works – crazy things happen with uploaded image and getting changes to take effect. Embedding page content, however, does seem to work.
However, it’s true, this seems to be a dead plugin in terms of any support or development.