I have been working my way through the Italian flashcards using the most common 2000 words deck. Although the percentage bar at the top of the page is steadily moving up the numbers for words mastered or learned have remained constant for several weeks. This is frustrating because it would be good to have a more accurate measure of progress. Is this a general problem or is it specific to my computer, an iMac? Also, it would be useful to know what is the difference between a word being learned and mastered?