The galleria will not load when clean urls is not active, because it composes the theme path using url() and so it constructs a path of the form

http://www.site.com/?q=sites/all/libraries/aino-galleria-c2f7a2b/src/the...

wich obviously gives a 404 error

To resolve it, i changed line 111 in views_slideshow_galleria.theme.inc from

$settings['themeURL'] = url($path ."/themes/{$settings['theme']}/galleria.{$settings['theme']}.js");

to

$settings['themeURL'] = base_path() . $path ."/themes/{$settings['theme']}/galleria.{$settings['theme']}.js";

Now it loads with no problems.

Some related posts: http://api.drupal.org/api/function/url/6#comment-6004

Thanx a lot, the module works like a charm. Saved my day movin a whole site from flash to drupal

Best regards