Slideshow from thumbnail not working

I use free NextGEN plugin and use Basic Slideshow for displaying my gallery. From the slideshow page I have a “View Thumbnail” link that takes me to thumbnail view of my gallery.

Once I click on one of the thumbnail, the related image pops up with a Left/Right arrow at the bottom of the photo.

When I click on either the left or the right arrow, nothing happens. The pictures don’t move along. Sometimes even the page freezes up.

Help? Hint? Thanks.