Caption alignment in NextGEN Imagebrowser

I’m using the Imagebrowser off of NextGEN Gallery v.1.8.3. to create a click-through gallery: http://wyofiletest.com/2011/08/imagebrowser-test/

It works perfectly, but I want to find a way to try to center-align the captions so they aren’t trailing out underneath the “Back” and the “Next” buttons. Since there doesn’t seem to be any way to control this in the NextGEN dropdown menu on the WP dashboard, I’m assuming it’s a coding issue.

Any ideas? Thanks in advance.