I recently migrated from one installation of Ubuntu to another, and in the process changed my username. I imported my public/private key pair into gpg, and while decryption (using my private key) works fine, whenever I attempt to encrypt something to myself with my public key I get the following warning message:
It is NOT certain that the key belongs to the person named
in the user ID. If you *really* know what you are doing,
you may answer the next question with yes.
After that it asks me whether I really want to use the key (I always answer "yes", because it is in fact the only key in my keyring and I know where it came from). I can decrypt stuff just fine, so why does gpg throw a hissy fit whenever I try to encrypt something? And how can I prevent this message from appearing again?