current input method not shown in mode line

[address@hidden]

Hallo fellow Emacsers,

I have just now realized that Emacs does not show the current active
input method in the mode line. Whatever input method I choose to try,
the mode line only shows a "-" in the left corner of the mode line
(followed by the indication of my default encoding). The input methods
I use (mostly german, rfc1345, and some chinese and japanese) all work
very well, online the correct status in the mode line is missing. Do
you have an idea, what the reason might be? I am using Emacs 23.0.91.1
(but it's the same with Emacs 22.2.1) on Ubuntu 9.04.

Thank you very much

George