This is not a thunderbird view related problem.
E-mail senders can send e-mail subject headers both in unicode characters or unicode characters mapped to rfcxxxx codes. It depends on the sender, not on thunderbird.
Probably your test e-mail subject was pure unicode.
I have sent the original e-mail to your primary address in launchpad to test it.
Thank you for checking this bug report.
This is not a thunderbird view related problem.
E-mail senders can send e-mail subject headers both in unicode characters or unicode characters mapped to rfcxxxx codes. It depends on the sender, not on thunderbird.
Probably your test e-mail subject was pure unicode.
I have sent the original e-mail to your primary address in launchpad to test it.