I'm using Workality Plus.
I have a 3 column portfolio page with 21 items in the folio. All of the thumbnails on the portfolio page are making use of the rollover.
When the portfolio page loads, it loads the top 12 portfolio posts and then when you scroll down it loads the remaining. The issue is that the thumbnail rollover does not work on the posts after the first 12.
A refresh etc doesn't make any difference. It looks like this is a bug.