I really love the idea of this plugin. (in fact, someone stole it and is selling it on CodeCanyon (unless that's you! if not, I can send you an email with the info)
I just installed your plugin and checked it on my site. It's only working on Firefox. Chrome and IE do not display the progress bar anywhere. Maybe it's because they are loading it behind an image. not sure.
I haven't tested it on Safari.
If you're available to trouble shoot this with me, can you give me an email address to send my site info to?
Thanks! Have a great day!