We're using U-Design theme (purchased at themeforest.net) on http://WinAPrizeHome.com.au & when I installed Black Studio TinyMCE plugin, I went into the Widgets area to use it.
After placing & saving 1 instance in a Homepage Column 3 widget provided by the U-D theme, all the TinyMCE buttons were there including U-D's orange shortcodes icon.
I saved this widget then clicked on the U-D icon to create a shortcode for a button, as a test. After clicking the INSERT button in the shortcode generator's popup dialog, Ithere was NO shortcode placed in the TMCE editor screen in your widget.
All the WP icons work; just the U-D doesn't. It DOES WORK in the normal page/post TMCE still.
I deactivated then reactivated all plugins, flushed all caches, still no-go with U-D's shortcode being generated in your widget.
I can email you a temporary Administrator login if it will help you check it out. And I can also email screenshots depicting the problem bits.
You can find out more info about U-Design theme at ThemeForest.net/item/udesign-wordpress-theme/253220
I tried WYSIWYG Widget before I tried yours but it wouldn't even come close to showing up any buttons (quickly uninstalled it!). Then I found your comment about BS-TMCE on his forum post & Voila. Nice, people.
Andon provides great support for his U-Design theme usage to customers so you may find the solution through him, if you can't find it yourself.
Black Studio TinyMCE is a superb plugin in its functionality. If we can get it to work along with U-Design's shortcode generator, which is part of his amazing theme, then we'll be in Seventh Heaven, so to speak!
Hear from you soon & thanks.