Problem with resize

Hello. Big Thank you for you plugin!

I have some problem with resize images. The pictures is not 100% x 100% size.

For example (info from browser).
Size: 150px × 73px (in scale 75px × 75px)

Image not have proportional, but post have big image.

Thanks

http://ww.wp.xz.cn/extend/plugins/wordpress-23-related-posts-plugin/