[Plugin: NextGen Gallery] Slowing down site

Hi everybody!
On my site I’m using NextGen Gallery, and the script itself works without problems!

But whenever I enable the plugin, the site seems to randomly slow down the page.. Like one load it can be regular loading time, and next it can be over 5 seconds. (On a fast connection)

I’ve tried pinging the site with Pingdom Tools, and according to that, the file that slows down the most is “lite.piclens.com/current/piclens_optimized.js”

Which doesn’t really make sense in my eyes, as I disabled piclens in the settings!

So I’m out of ideas what to do..
Anyone got suggestions?
(Or if it gets to the VERY desperate, an alternative to NextGen?)