Weird graphical glitch showing photo's duplicated in an endless list

[LaurensdeGraaff]

Its a very nice plugin, but I'm having a issue which I can't debug

Photos are shown duplicated while I added theme once.
Issue can be found on: http://beta.derailedrevolution.com/portfolio/ (password: beta345), then opening a category (e.g. behind-the-scenes) and scrolling down.

All photos are compressed to a max of 3000 x XXXX and =<1mb (most pictures are around 3000x2000).

edit:
A refresh of the page solves the issue. How could I permanently solve this issue?
Opening and closing a photo causes the issue again.

[pyronaur]

Hey @lauwie007 - did you manage to solve this? Sorry for responding "a little late" :)