Firefox is not fine. If you think it is, please tell me how to disable BASIC http auth in it. (This is a serious problem, as it will send passwords unencrypted

Firefox is not fine. If you think it is, please tell me how to disable BASIC http auth in it. (This is a serious problem, as it will send passwords unencrypted over a non SSL connection, and my users have been trained to type their sso password into every box they see (I know.... Not my doing)).