I've posted a new build for Simple Gallery in the downloads section (members only).

New Features Include:-

• In the main module and simple gallery latest, you can now choose an additional thumbnail type called square thumbnails (the default has been named proportion thumbnails). These will create perfect squares out of images for albums and photos, you can also specify the dimension of the square. Some cropping may occur to create the square, see a live example here.

Fixed Bugs Include:-

• Updated the lightbox script to no longer use a deprecated command in jquery. This will allow you to upgrade jquery to a higher version.
  
• Removed some blank html at the top of the gallery when the user has no items on the command bar and an album has no description.

Thanks again for all your feedback!