The problem is a compatibility issue between Clipcart 1.2 and Cart66 Lite 1.4.9. Downgrading to Cart66 Lite 1.4.8 fixes the problem until next versions of Cart66 and Clipcart.
http://themedy.com/forum/discussion/795/cart66-shortcodes-do-not-show-up-on-product-page-dropdown-
I don’t have Clipcart 1.2 but I have that same issue on my Custom Post types
Still doesn’t work in free version and “sometimes” in paid version (no cache plugins or other plugin conflict and on Genesis framework).
If you are using custom post types you have to make a tiny tweak to your functions.php file to enable the cart66 pop up screen to work. We’ve got a new, public, knowledge base available that includes a post about how to get the pop up product selector working on custom post types.
I have a basic WP v3.4.2 installation with the only changes to WP Settings>Permalinks being set to Post name /%postname%/ and using Zenshop v1.0.0 theme plus the required Cart66 Lite v1.5.0.2 and WP-PageNavi v2.83 plugins.
In order to get the Add Cart66 shortcode icon to work i.e. not display a blank pop-up, I added this code to the theme’s function.php, just before the last ?>
/* CUSTOM PRODUCT SLUG */
function my_products_pages() {
return array('products');
}
add_filter('cart66_add_popup_screens', 'my_products_pages');
Then the product editor icon, (which is gray for me) works in both visual and HTML modes.