I uploaded a new version of the file today.
I was having a problem getting the add to cart button to work. After some work and timely information from Boxtel, I figured out that the opening form statement needed to be moved. If you don't have the location for the previous/next navigation buttons set to 1 or 3 in the admin panel, the opening form statement is not created and the button doesn't work. I moved the form statement out of the if statement, and now it works no matter what your settings are.
As well, I updated the readme to include the fix for adding the last item on the list. You should be able to cut and paste to make the changes now.
Thanks for the great mod.