Strange redirect

Sometimes some requests are redirected to a strange superdomain, for example my site http://www.alexnetwork.it, sometime you’re redirected to:

http://false/?setCookie=1&contUrl=www.alexnetwork.it

also if it loads correctly some files are redirected also at:

http://false/?setCookie=1&contUrl=real_file_url

Probably the superdomain function (that i don’t know which one is) gives false as result.

I’ve set correct website info in the settings.
Any clue?