It appears if only the teaser AJAX Cart block is used and the Full AJAX cart ...

It appears if only the teaser AJAX Cart block is used and the Full AJAX cart block is not used. It should be reproducable that way.

The module is supposed to work like that. The ajax libraries are associated with the main cart block. Adding the libraries both in main cart block and in teaser cart block will be redundant. Also the bug that you pointed out does not relates to the current issue. Please create a new issue for this.