I'm so sad. NextGen worked great until the recent update (and even the fix for the update). Broke many images on my website, slowed my pages to a crawl, and is confusing. So much work now for me to fix the mess that this plugin update created on my image-heavy site. I'm running the default WP template, 2012, unmodified and still disaster. A totally irresponsible update!
Update: Well, at least you can rollback to a previous version. This seemed to fix things with a minimal effort. I had upload the older version of the plugin and reset some configuration options, but now I am back in business.