[Plugin: WordPress Theme Demo Bar] Demo bar when adding a subfolder

Hello,

This is a nice plugin and it works but I have an issue.
I’m using it for a websites where you upload/download themes and it the visitors have the possibility to live preview the themes before download.

If the files are in a subfolder which is in the main theme folder, the demo bar does not appear anymore.

For example:

This way it works:
http://myblog.com/?themedemo=sometheme
path to theme is: wp-content/themes/sometheme/

This way it doesn’t work:
http://myblog.com/?themedemo=sometheme/subfolder
path to theme is: wp-content/themes/sometheme/subfolder/

Can anyone give me a solution?

Thanks you,
Alex

http://ww.wp.xz.cn/extend/plugins/wordpress-theme-demo-bar/