One-Time Use of Remove Card in Flashcard

We are using Flashcard version 2012080800 on Moodle 2.6.2. When running flashcard in free play mode, one is supposed to be able to remove cards as they are learned. The link/button for removing cards is visible when first starting to free play, but once selected, that link/button is no longer available to remove subsequent cards. Further, I question if it is really removing cards, as the total card count does not appear to change.

I have read the information at https://moodle.org/plugins/view.php?plugin=mod_flashcard about the two divergent versions, and might like to move to using the newer version, but I have not been able to ascertain whether this "remove card" feature in free play works correctly.