deb64a:~# aptitude update
Reading package lists... Done
Building dependency tree... Done
Reading extended state information
Initializing package states... Done
Reading task descriptions... Done
Building tag database... Done
Get:1 ftp://ftp.de.debian.org testing Release.gpg [189B]
Hit ftp://ftp.de.debian.org testing Release
Err ftp://ftp.de.debian.org testing Release
Get:2 ftp://ftp.de.debian.org testing Release [35.4kB]
Ign ftp://ftp.de.debian.org testing Release
Hit ftp://ftp.de.debian.org testing/main Packages
Hit ftp://ftp.de.debian.org testing/contrib Packages
Hit ftp://ftp.de.debian.org testing/main Sources
Hit ftp://ftp.de.debian.org testing/contrib Sources
Fetched 35.6kB in 1s (18.5kB/s)
Reading package lists... Done
W: GPG error: ftp://ftp.de.debian.org testing Release: The following
signatures couldn't be verified because the public key is not
available: NO_PUBKEY 010908312D230C5F
W: You may want to run apt-get update to correct these problems