I'm trying to access the same linux box from two computers. I ssh'd in from the first without a problem but later I was not allowed to ssh in from the second. The error I got was something like

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
Add correct host key in /Users/viniosity/.ssh/known_hosts to get rid of this message.
Offending key in /Users/viniosity/.ssh/known_hosts:5
RSA host key for 123.456.78.910 has changed and you have requested strict checking.
Host key verification failed.

Note that I changed the above IP for my own protection. :o) My question is: should I disable strict checking (if so.. how?) or else, how do I copy a key from one box to the other?

Thanks in advance..

Figured it out.. I erased the file /Users/Viniosity/.ssh/known_hosts and the problem is fixed. Obvious in retrospect..