Hello,
You receive this mail as the translation of Debian Installer in your language is not complete as of now.
We (the Debian Installer team) just released the beta 2 version of D-I, which is meant to be the "really close to be final version" of the installer for Debian squeeze.
Very soon now (the date is not completely decided), we will release a very final version. So, please, update your translation AS SOON AS POSSIBLE. Please consider that you have less than one week.
In case you need information about getting material or how to commit, please feel free to ask me. But, really, hurry up!