Thumbnail Resizing

I am having trouble resizing thumbnails in my site. I am looking to reduce the size of the square thumbnails in the item display pages only. I went into the General Settings of my Omeka admin panel and changed the Thumbnail Size and Square Thumbnail Size fields to 100 but all appear to still be displaying 200x200. Is there a place in my theme code where I can edit this directly? qcarchives.com/sci is the site and I am using the Santa Fe theme

I think I found my answer at http://omeka.org/forums/topic/error-message-images-not-sized-properly . Looks like it will only apply the new size to new items uploaded into the system but I need to manually change the size of existing square thumbnails. Good thing we don't have too many items uploaded yet!