Hi artur.sadlos,
When your site is hosted as a dedicated website these problems may not take place.
Sharing various domains/websites on one and the same IP means that one or more bad apples there may give the whole basket of apples a bad name. That is what has happened in your case, all of the IP blocked, because the hoster is not acting towards abuse by others on that same IP. In that case you are not doing anything wrong, but you are a victim of such sloppy hosting abuse policies. Similar message but a bit differently put came from our forum member Eddy in his earlier reply.
polonus
P.S. Also consider the CMS technology used: http://www.dtelepathy.com/blog/philosophy/do-you-really-need-a-cms
IP info: Server IP(s):
198.185.159.145
198.49.23.144
198.49.23.145
198.185.159.144
D