Well, using ssh on AIX 5.3 I get the same response.

However, using telnet it works as expected.

I used to build openssh myself, but currently use the openssh provided by IBM.

Seems that sshd does not start the session the same way telnetd does. The solution will lie in an examination of how sshd initiates the initial shell compared to telnetd.

I guess you could make exit an alias for logout. exit works fine

michael@x054:[/home/michael]type exit
exit is a shell builtin.

Way way back when - logout was a built-in for the csh.

I have always used either ctrl-d, or exit as the way to leave a shell.

So, I guess first we need to hear which shell are you using.