I use hamachi for a minecraft server, and this problem just abruptly surfaced. Me and my friends all play on my server, all of them can connect except for one. He could connect for a day, but the next say he could not connect. When he tries to ping me on hamachi he gets request timed out, but i can ping him fine.
Got the same problem. Tried adding hamachi to the router and firewall. Changing networks. But still nothing. Its wierd, 'cause before reinstalling win7 it worked fine, but now it just rejecting their "pinging".. Another sollution please! :)