I stumbled upon your plugin and since I've got a few thousand images uploaded with NextGEN Gallery I needed to try it out.
However, when I click on the bulk optimize link it tells me "We have 1 images to optimize.", but there are currently 5.261 images in my galleries (website: http://mafia-daily.net/).
Do you have any idea why it's not working properly?
Take a look at the debug file here: http://mafia-daily.net/debug_ewww.txt
Works fine for the images uploaded with the internal WP media uploader.
Also, is there a way to optimize just a single gallery at once?