On hovering one post (In archive or homepage), it works as expected, loaded pin button. But if you hover any second post, it'll not work properly, at least in my case.
I looked at console of Chrome, I got following error:
Uncaught TypeError: Cannot call method 'removeChild' of null repated (2 times) wpsocialite.js Line: 7
I have removed the Pinterest option currently from my site. If you need to investigate, I'll check the option and will give you link.
I hope you can resolve it soon.