[Web-cyradm] Problems with language selection, only english

[SeeDyX]

Hi

I have the problem, that web-cyradm is completely in english. on the 
login page i can chose between the languages, (and usually there is 
"Deutsch") preselected, but that doesn't have any effect. even if I 
chose another language there, only the footer changes a little bit (the 
persons written behind "translated by" change ;)) but everything is 
still in english.
I'm using a debian sarge system (php4 / apache2) and web-cyradm 0.5.4
I think, that maybe I only need to install some additional packages, but 
I don't which ones?

Can anybody help me?

Thanks,
Sebastian