german mirror "badsig"

[Stefan]

Hello all,

I noticed "badsig" using apt. To solve the issue I tried the things
http://askubuntu.com/questions/1877/what-is-the-easiest-way-to-resolve-apt-
get-badsig-gpg-errors

.... and others.
Nothing solves it. So I changed the mirror in sources list from  german to 
english server
deb http://de.archive.ubuntu.com/ubuntu/ precise main restricted universe 
multiverse 
to 
deb http://en.archive.....

no errors then.

 I wrote this mail to ftpmaster at ubuntu.com ... no such user...
Whats going wrong?

tia
Stefan