PGP Signing Emails in Evolution Displays Wrong in OE6

[MG-Cloud]

Hi,

I've just recently starting PGP signing all my emails in evolution. It's come to my attention recently that, to Outlook Express users, that the message body
appears as an attachment as well as the PGP signature.

http://www3.telus.net/mguzman/sigerr.jpg has an example of the problem. It's kind of wide so I'm not embedding it in the forum.

Is there any way to fix this error besides not signing these emails or switching mail clients?