quail-help displays on the screen.Is this a know bug?
Make sure that *quail-keyboard-translate-table* is correctly set.
If this variable is left unchangend, Mule assumes your keyboard layout is same as vt100 and displays the layout for vt100. Especially if you are using a JIS keyboard, you have to put the following in your .emacs:
(setq *quail-keyboard-translate-table*