WWW site not available

I posted this problem to ...windowsxp.general but no solution was
found (June 26). The problem is: With Arris modem I'm getting internet
to two computers: one is connected with usb and the other one with
network plug. I suppose I don't use ICS: the "usb connected" machine
may be off while I can use my second computer... And with this second
machine there is a problem: I can't load the site www.polityczni.pl ,
so far this is the only site that makes problem. I made PING, obtained
the number but no result. I was trying to switch on and off my cookies
as well as my AVG (Free edition). With IE it keeps loading without
end, with Firefox it gives something like (not precisely, sorry):
" Wrong redirection. Firefox detected that server redirects the
request in the way that makes the comletion impossible...".
Do you see any reason for that? Thank you...

I changed my IP address from private to public one; now it works...