every time I receive an encrypted or signed message. GpgOL shows that the used key does not claim the address like "Johnny.Leone@example.com".
I'm using GpgOL with an exchange mail server which "translates" the receiving address to a capitalization address like "Johnny.Leone@example.com". All these emails are also sent over the exchange server. When I'm receiving mails from external mail servers without capitalization in the addresses there is no such problem.
The used keys also has separate identities for these addresses.