site doesn't work for me, same message that it is down did the address get changed?
If you are on windows, start->run-> "ipconfig /flushdns" (without quotes) and then in your navigator press Ctrl-F5 in bitcoin.cz page to reload from site and not from cache
nope didn't work, could it be that i'm in firefox? and your english is fine

The Ctrl-F5 works fine in Firefox. May be your ISP/DNS provider didn't update the DNS record to point to new IP.
Try puting an aleatory character in URL as GET parameters like mining.bitcoin.cz/?renew. This will be interpretated for firefox as new page, and not load it from cache
P.S.: Thanks for tell me that my english is fine. I do my best.
EDIT: URL mistake