Can't check message signature

[lusfert]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: RIPEMD160

Hello.

Recently I submitted my key to PGP Global Directory and received a
verification request. I can't check it't signature, I see the following:

OpenPGP Security Info

Unverified signature

gpg command line and output:
C:\\Program Files\\GNU\\GnuPG\\gpg.exe --charset utf8 --verbose --batch
- - - --no-tty --status-fd 2 --verify
gpg: armor header: Hash: SHA1
gpg: original file name=''
gpg: armor header: Version: PGP Universal 2.0.3
gpg: Signature made 09/29/05 19:40:01 using RSA key ID CA57AD7C
gpg: WARNING: signature digest conflict in message
gpg: Can't check signature: general error


What may be a problem?
GnuPG 1.4.2, Windows XP SP2, Enigmail 0.92.1.0


- --
Current OpenPGP key ID: 0x500B8987
Fingerprint: E883 045D 36FB 8CA3 8D69  9C79 9E35 3B56 500B 8987
Keyserver to use: sks.keyserver.penguin.de
Encrypted mail preferred.

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.2 (MingW32)

iD8DBQFDPTyAnjU7VlALiYcRA7O5AKC1tovmDY+eIyQoS6AffJI4bZRPjwCeKpob
UuyDPqW8WNqj3SgVcd53Crk=
=0pX/
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