when logged in with an account that has /bin/bash for a login shell, the commands 'set -o vi' and 'set -o emacs' do not seem to work. 'set -o' reports that the correct option has been set, but the shell doesn't respond correctly. Using 'exec bash -o vi' solves the problem, after which 'set -o vi' and 'set -o emacs' work correctly.
*** This bug has been marked as a duplicate of 21222 ***
I found a different variation of this bug. If you put `set -o vi' in root's .bashrc no editing mode works when you login. If you type `set -o emacs' that works, but you can't get vi mode to work. But if you remove the `set -o vi' from .bashrc then emacs mode works immediately and vi mode works after `set -o vi' from the command line. Haven't tried this from a non-root account.