No more featured post thumbnail in CPT 'campaigns' editor

Hello,

You’re plugin is truly awesome.

I only have one problem : after activating the plugin, I can’t no more choose a featured post thumbnail in the post editor (CPT ‘campaigns’). I’ve noticed that this functionnality comes back when I deactivate your plugin.

I’ve put this in my function.php :

add_theme_support( 'post-thumbnails', array( 'download' ) );

and this too :
add_theme_support( 'post-thumbnails', array( 'campaign' ) );

But unfortunately it doesn’t work. Any help would be much appreciated !

My install (on localhost)
WordPress : 3.6 RC1
Framework : Genesis

Thank you for any help you could provide and keep up the good work 🙂

Mat

http://wordpress.org/extend/plugins/appthemer-crowdfunding/