My ISP (AT&T) sends warnings from time to time about connections from my IP to a botnet. These seem to all be related to operating the Bitcoin client. This latest warning includes the target IP which is  92.243.23.21. I understand that the connection to that host is used to boot up the bitcoin client. Is it safe for me to block that IP in my firewall? And, has anyone else seen similar warnings from their ISP about this, or other IP used with the Bitcoin client?

Thanks!
BlueWall