[Plugin: NextGEN Gallery] Image resizing problem in cache folder

I’m currently having this issue with the quality of the resized photo in the cache folder.

Resized to 500 x 736px – http://dayna.me/wordpress//cache/436__500x_coffee.jpg

Original – http://dayna.me/wordpress/wp-content/gallery/layouts/coffee.jpg

Thumbnails have no issues – http://dayna.me/wordpress/wp-content/gallery/illustrations/thumbs/thumbs_coffee.jpg

This only happens to .jpg photos. .png has no issues.

Please help. Thanks!

http://wordpress.org/extend/plugins/nextgen-gallery/