Why does 'ssh' and 'scp' work to one and not another?

[Josef Lowder]

.
Why does 'ssh' and 'scp' work to one and not another?

$ scp testm2p joe at 192.168.0.68:/home/joe/ -- This works to computer
"68" on my network

But why does the following not work to computer "73"? Both have sshd started.

$ scp testm2p joe at 192.168.0.73:/home/joe/
Warning: Permanently added '192.168.0.73' (RSA) to the list of known hosts.
joe at 192.168.0.73's password:
Permission denied, please try again.
joe at 192.168.0.73's password:
Connection closed by 192.168.0.73
lost connection

== I also tried this (which works to "68") and it also does not work to "73".
$ ssh 192.168.0.73
joe at 192.168.0.73's password:
Permission denied, please try again.

What do I need to fix to get these both to work?