I wasn't able to encrypt to someone even though their key is on my keyring. I get a message that no valid and trusted key could be found for the recipient. The key isn't revoked, not expired, and my signature is on his key. Can anyone explain this? Mandriva 2007, Kmail 1.9.4, gnupg-1.4.5-1.2mdv2007.0, gnupg2-1.9.22-2.2mdv2007.0