User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 Upon launch, Master password can be easily bypassed without entering the password by: - Clicking "Cancel" button repeatedly - Pressing "ESC" key repeatedly Reproducible: Always Steps to Reproduce: 1. Launch the problem 2. Press cancel button or esc key repeatedly 3. Password bypassed

The Master password doesn't control access to the application, only to the password list. Even if you can't fetch new mails, you can still read the old ones.