[Plugin: Promotion Slider] Images not centering

Hey, great plugin but images are not centering for me. I have tried margin: auto; – but doesn’t work.

I can’t crop the photos to the exact size because images are used throughout the site in different sizes. Timthumb handles it fine, but can’t seem to add timthumb to Promotion slider code.

http://www.mogultheory.com/tech

http://wordpress.org/extend/plugins/promotion-slider/