GnuPG and email clients - Help I'm an Idiot

[Rox Off]

I have setup a php form to encrypt data and email it to me. This part works. Now when I try import to Outlook or Outlook Express via the GnuPG plugins, I keep getting errors. It apprears the keys are fine. But when I try to decrypt the message I keep getting invalid key or other errors.

Any suggestions for a braindead person?