I just tried out the Expansion Section for the Lower Intermediate level classes, and to my disappointment, for each of the six lessons that I just tried out some of the links to the audio recordings did not work, i.e. nothing happens when you click on the appropriate button. For lesson five, not one single such link worked!!
Have those recordings ever been made, or are the links just there in case you decide to provide the recordings at a later time? If that is true, you should at least enable the function that changes the mouse pointer to a hand (or some other previously chosen item), whenever the arrow is placed above something that leads to or activates something, so that one sees more rapidly that a link etc. actually does not exist.
To some extent, a "bug" may be involved, since the first of the recordings of the sample sentences, for a lesson, never worked, in any single case.
I also noted, yesterday, that in several cases, the recordings in Italian in the vocabulary with audio section does not at all correspond to the translations provided. For instance, "I am sorry" was provided as the translation of a sentence about smoking being prohibited, that only started with "I am sorry".
Finally, I hereby suggest that you provide links, in the vocabulary, to some respected, free online dictionary of Italian, so that more complete coverage of the words' meanings is made available to the users in a time-efficient manner; perhaps you can even negotiate an agreement, for your members, with an online dictionary that is not otherwise free to use.