port forwarding trouble

[Frederik Eaton]

Hi all,

When I set up multiple tunnels from remote hosts to ports on
localhost, I get the following error when I try to use them:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!

(even though the keys haven't changed on the remote hosts). I assume
this is because the known_hosts file doesn't include port numbers.
However, this means that at least as I have things set up tunneling is
quite unusable. Is there a configuration option that I'm forgetting to
set which will cause ssh to differentiate between various ports on the
same host?

Thanks in advance,

Frederik