After I've upgraded to version 3.8, I've noticed the layout in the dialog box for Featured Image is broken. When I try to select a Featured Image from my NextGEN gallery, I can select a gallery but I'm unable to click on the pagination. I only have the option of selecting the images from the 1st page.
To reproduce, add theme support for post thumbnails, then edit a page/post. Click on Featured Image and select an image from the NextGEN gallery, then see the dialog/modal box.