I have the same problem as an older topic:
“I am currently working with the portfolio showcase and I want the thumbnail to link to a URL. Consequently, I changed the portfolio thumbnail link type to “Link to URL” and that works well. The problem is that only the thumbnail image links to the URL, but the portfolio title links to the portfolio item. Thus, depending on what part of the thumbnail you click on it brings you to 2 different pages. “http://www.swiftideas.com/forums/topic/portfolio-thumbnail/
But I can not download the suggested file as it is not available any more.