Hi there, I've tried for many hours to get your plugin working, but all I get after creating a carousel, uploading the images, and inserting the appropriate code in the php theme file, is a vertical UL of all if the images, no skin, and no navigation buttons.
It is as if the plugin is not seeing its own CSS or JQUERY code at all, and my suspicion is that's what's happening.
I'm using a custom child theme I created, and I noticed you are using
the "WP_PLUGIN_URL" constant in your php code, which the WordPress codex says should never be used in plugins. ( see.... http://codex.wordpress.org/Determining_Plugin_and_Content_Directories ). So I think your code to locate the CSS and JS files is failing somewhere if the users directory structure does not happen to be standard, as mine isn't.
Unfortunately I don't have the time to debug this further for you so I'll have to move on to another plugin, but would appreciate if you could post a fix for everyone out there like me, as it's very frustrating to waste a lot of time on code bugs like this.