ssh - middle man in the attack

[taufik]

Dear All...   i have some complication with ssh, i'm using ssh to connect to another server this is the error that i get   "It is possible that someone doing something NASTY, someone could be eavesdropping on you right now (MAN-IN-THE-MIDDLE ATTACKE)! it is also possible that the DSA host key has just been changed, the fingerprint for DSA Key sent by the remote host is ... add correct host key in /root/.ssh/known_host2 offending key in /root/.ssh/known_hosts2:3 DSA host key is change."   what should i do now?   thank you, -taufik-