[sisyphus] apt-get update: "file was not signed with a known key"

[Pavel S. Khmelinsky]

[root на gate root]# apt-get update
Get:1 ftp://updates.altlinux.com Master/2.2/i586 release [694B]
Err ftp://updates.altlinux.com Master/2.2/i586 release
file was not signed with a known key. Check if the proper gpg key 
was imported to your keyring.
Fetched 694B in 2s (274B/s)
Failed to fetch 
ftp://updates.altlinux.com/Master/2.2/i586/base/release  file was 
not signed with a known key. Check if the proper gpg key was 
imported to your keyring.
Reading Package Lists... Done
Collecting File Provides... Done
....

Что это может значить?
пакеты alt-gpgkeys-0.1-alt11 apt-conf-sisyphus-1.9-alt1 -- все 
родное мастеровое.
На соседней машине нормально индексируется....