[Plugin: NextGEN Gallery] Thumbsize Size

Require solution to fix thumbnail size.

Nextgen ver 1.6.2
thumbnail size : 100 x 75
Fix dimension is set to ignore aspect ratio.
My picture is 1024 x 673 pixel and 1024 x 662 pixel.

Problem: The thumbnails looks distorted. See http://www.propertyhomes.sg/the-glyndebourne/

When I played around with the dimensions, the height will change but not the width. If i set the width to be more than 200px, error will occur
“Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 601 bytes) in /home/homebuye/public_html/wp-content/plugins/nextgen-gallery/lib/gd.thumbnail.inc.php on line 933”