Using of subkeys for encryption

[Patrick Plattes]

Hello,

i have a problem while encrypting a message. I'm using the OpenPGP Card 
but i think the Problem doesn't depends on it.

I've got a an decrypted e-mail and if i try to encrypt the e-mail i got 
a "gpg: public key decryption failed: wrong secret key used". The ID of 
the used key is an ID an a subkey. Usualy I don't use the subkey for de- 
and encryption, but i don't know anythink about the subkeys. According 
to the GnuPG Handbook it should work to use the subkey.

Have a nice day and a good morning :),
Patrick

Here is the complete output:

patrick at Dragon:~$ gpg very_secret.gpg
gpg: encrypted with 2048-bit RSA key, ID XXXXXXXX, created XXXX-XX-XX
      "Another Person <Another at Person.de>"
gpg: encrypted with 1024-bit RSA key, ID 37BDF910, created 2005-09-21
      "Patrick Plattes (Mr. Parity) <patrick at erdbeere.net>"
gpg: public key decryption failed: wrong secret key used
gpg: decryption failed: secret key not available
patrick at Dragon:~$ gpg --list-keys 37BDF910
pub   1024R/F7E086A6 2005-09-21 [expires: 2008-09-20]
uid                  Patrick Plattes (Mr. Parity) <patrick at erdbeere.net>
sub   1024R/37BDF910 2005-09-21 [expires: 2008-09-20]
sub   1024R/8A270C95 2005-09-21 [expires: 2008-09-20]

patrick at Dragon:~$ gpg --list-secret-key         
/home/patrick/.gnupg/secring.gpg
--------------------------------
sec   1024D/CE4CF5A4 2003-04-23
uid                  Patrick Plattes (Mr. Parity) <patrick at erdbeere.net>
ssb   4096g/D7173E45 2003-04-23

sec>  1024R/F7E086A6 2005-09-21 [expires: 2008-09-20]
      Card serial no. = 0001 000004FB
uid                  Patrick Plattes (Mr. Parity) <patrick at erdbeere.net>
ssb>  1024R/37BDF910 2005-09-21
ssb>  1024R/8A270C95 2005-09-21