[Plugin: NextGEN Gallery] Thumbnails are cropped

Hi there,

i installed NextGEN Gallery a while ago, and everything was good.
Now i look at my gallery’s and all the thumbnails are cropped.

Look here:
http://www.runningplus.nl/wordpress/foto-film/marathon-rotterdam-2010/

I searched for settings in the plugin, but i couldnt find it.
Maybe tou can help me, get it to fix>

Thanx in advance

Greetz,
Remco