keyboard settings

[Mark-Walter@t-online.de (Mark Walter)]

After reinstalling all GNOME packages my keyboard doesn't print umlauts
anymore. LANG=de ( out of /usr/share/locales ) is set and also some values 
in the /etc/X11/XF86Config:

    XkbModel    "pc102"
    XkbLayout   "de"
    XkbKeymap   "xfree86(de)"

I've just tried to execute my signature and this error message appears:

perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
        LANGUAGE = (unset),
        LC_ALL = (unset),
        LANG = "de"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
        LANGUAGE = (unset),
        LC_ALL = (unset),
        LANG = "de"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").

Which package is missing ?

-- 
echo '$e=5;$p=3;$q=13;$h=$p*$q;while(($e*++$d)%($h-$p-$q+1)-1){};while($t=subst
r("82758c1b8939c7ef5c5d0   1eaa4aa38516aed555+9fe27fd0f5b0b464474b2316eac~~~~   
Mark-Walter@t-online.de  ~~~~390a03",$i,3)){$_.=pack"I",(hex($t)%$h)**$d%$   
h+95;s/_/+/g;$_=($i+=3)%2?uc:lc;print"$_\n";}'|perl -ne"chomp;s/|~|\s*
Mark-Walter@[^~]*//g;print"|perl