[Plugin: WP Photo Album Plus] Slideshow height problems

I’ve just updated WP Photo Album Plus to 4.6.5 and I’ve now got a problem with my slideshow. The images are 640 pixels wide, as set in Table IB-1, but no matter how I alter the Full-size height in Table IB-2 it stays stubbornly at 693 pixels and all my images are have a horrible vertical stretch. I have no idea why it is 693 pixels. It used to work fine with a height of 480 pixels, or whatever I put in the Full-size height box. If I change the number of pixels in the Full-size width box this seems to change fine.

What can I do to get the Full-size height to the size I want?

Thanks for any assistance in advance it’ll be much appreciated.

http://wordpress.org/extend/plugins/wp-photo-album-plus/