umlaute not recognized

[Tim Häring]

Hello,

I have a problem with german "Umlaute" like ä, ö or ü in emacs.
If I write a text-file in e.g. gedit like the following:
Hällöle
and open it with emacs I get the following:
hällöle

Don`t know what the problem is. Becaus it is no problem to write Umlaute 
in the buffer. If I modify my file to
hällöle
äää
and save it with C-c C-s, exit emacs with C-x C-c, open emacs again and 
load my file, the Umlaute in the second row were correctly displayed.

I am relatively new to Linux und Emacs. So maybe the problem is very 
trivial. I am using GNU Emacs 23.1.1 under Ubuntu 10.10. I installed 
emacs using
apt-get install emacs

Thanks for every hint.

TIM