[MlMt] Problem with GPG encryption

[Robert Goldman]

Whenever I try to send a message with GPG encryption, I get an "OpenPGP 
encryption failed dialog box."  The horrible error message (I know -- 
this is GPG's fault, not MailMate's!) looks like this:

KEY_CONSIDERED
<public key fingerprint>
0

interestingly, there are 3 copies of this for each fingerprint, and 2 
fingerprints listed, one for my public key (presumably for signing? or 
for keeping a copy in sent?) and one for that of the recipient.

after that I see

INV_RECP 10 <destination email address>
FAILURE encrypt 53

... and I'm offered the choice of "Cancel" or "Trust Once," which seems 
to suggest that this is a trust failure.

But the trust level on my recipient's key is 5 and mine is 6.  So why 
does this fail?

I'm using the gpg2 implementation from MacPorts.

Oh, and this works fine if I press the "Trust Once" button, but it's 
kind of irritating.

thanks!