Strange Gallery Problem - only shows one image when I try to add new image

Having a lot of trouble with a gallery on this dev site, on this page:
http://callahansign.designbyansley.com/installation/

The biggest issue is that when I try to add a new image, the rest of the images disappear and the gallery only shows one. However, from the edit screen (both in the Text tab and View tab) I can see that all the images are still there.

Weird right?

When I delete the new image from the gallery, all the other images show back up.

Also, if you go to the Products page, you can see there are strange differences in the gallery layouts. I had to style this one specifically because there were gallery-1 styles being applied to it that were not in the stylesheet.

Can anyone help? Very weird. Thanks!