Shadowbox JS frame jumpiness

I have been using SB-JS for a while and the strange (to me) behavior of the frame moving down and then up when moving from one image to the next. This, it does whether the height would change or not. I have looked at the CSS and could not find a hint as to why this is happening. Could the plugin author, or someone knowledgeable in javascript steer me in the direction of stopping that jumpy transition?

A related question I have is the possibility of true A-B fade, as one image fades out, the next one fades in. I can see the complexity of this when the frame needs to be resized to accommodate different image sizes. I hope it is a possibility.

Thank you,

Cemal

http://wordpress.org/plugins/shadowbox-js/