Found the problem!!
The file that controls the way calender listing is displayed is modules/events_calendar_listing.php

I uploaded the file that came with the original mod. I just downloaded the updated files found here on this thread, and uploaded just that file to my server and now it displays correctly all the events!

Checking both files now to see what's the piece of code that was causing the problem. Hopefully someone else with the same issue can find it helpful.