If you use the command "set -o vi" in /etc/bashrc or
in /etc/profile, then command-line editing doesn't work.
If you try and use one of the VI command to scroll through
the history list such as ESC-k k k, you just get a beep.
If you remove the "set -o vi" command from /etc/bashrc
and /etc/profile, and then type in the command from the
command line, then it works fine.

When the command is in the rc file, and you type "set -o
emacs" at the command line, then the emacs mode works.  If
you then attempt to switch to vi mode "set -o vi," then
command-line editing fails.