Image width cropped in Slideshow

My images are being cropped in Slideshow to a width of 978px, regardless of the original width. The height is ok. In the media gallery, the images was uploaded as 998px x 425px, and the same dimensions are displayed in the Media Gallery. But in the Slideshow code the image size is 978px. Please help!

Here’s my site: http://wpdev.madwills.com/
I’m using Slideshow version 2.2.11.

Thanks!

http://ww.wp.xz.cn/plugins/slideshow-jquery-image-gallery/