So ShareThis have just released a major version of their WordPress plug-in, v5...up from 4.1. With a jump that large, I'm guessing that a lot has been added / changed.
So, why is the plug-in only compatibility tested upto 3.0.2? That's as far back as November 30, 2010! And worse still, ShareThis don't implement a Changelog so I can't even hazard a guess of what might break when I upgrade.
Well done ShareThis, punish people that keep on top of upgrading the WordPress core