can't verify

[kurokirasama]

Hello, I got this output:

$ cpansign --verify
Executing gpg --verify --batch --no-tty --keyserver=hkp://pool.sks-keyservers.net:11371 --keyserver-options=auto-key-retrieve /tmp/D6K8mfHh2q
gpg: Signature made dom 02 nov 2008 09:53:47 -03
gpg:                using RSA key 770B3C4393B84C15
gpg: requesting key 770B3C4393B84C15 from hkp server pool.sks-keyservers.net
gpg: Total number processed: 1
gpg:     skipped PGP-2 keys: 1
gpg: Can't check signature: No public key
==> BAD/TAMPERED signature detected! <==