Error on decoding message

My company have upgraded from office2007 to 2010. Before, i already used 
gpg4win and it's outlook plugin to handle pgp mail

What steps will reproduce the problem?
1. Decrypt any existing pgp message via button in ribbon
2. Select the key and enter the passphrase

What is the expected output? What do you see instead?
Got an Error box "GnuPG Error" "gpg: verify signatures failed: unexpected data"

What version of the product are you using? On what operating system?
BETA-19 on Win XP

Please provide any additional information below.

I also be able to decode the message in the read plane "by hand": Copy it into 
a file and pass it to the gpg.exe on command line.

How to debug it? Is there any logfile? Please also notice, that i need to 
support a idea.dll beside the gpgp.exe because it is used in the keys.

D:\Programme\GnuPG>gpg --version
gpg (GnuPG) 1.4.9 (Gpg4win 1.1.4)
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Home: C:/Dokumente und Einstellungen/#########/Anwendungsdaten/gnupg
Supported algorithms:
Pubkey: RSA, RSA-E, RSA-S, ELG-E, DSA
Cipher: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH
Hash: MD5, SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
Compression: Uncompressed, ZIP, ZLIB, BZIP2

Original issue reported on code.google.com by Guido.Ja...@gmail.com on 16 Nov 2012 at 8:34

anonghosteam / outlook-privacy-plugin

Error on decoding message #45