How to reproduce:
# Start with an empty key ring, create an OpenPGP key pair.
# Open //Notepad// and check //Encrypt for others//.
# Enter `werner.koch@gnupg.com` and press the Return key.
* Observation: Briefly, "Error: No matching certificates or groups found" is displayed. Then the error disappears and the icon changes from a red one to a blue one.
# Go to the next recipient input, enter `wk@gnupg.org` and press the Return key.
* Observation: The same as before happens for the second recipient input.
* Observation 2 (the actual bug): In the first input the icon turns red and "Error: No matching certificates or groups found" is displayed.