Alec,

The check "$unseen != $old_unseen" in the new function rcmail_send_unread_count() created in r2959 prevents the call of the JS function set_unread_count_display() that inserts the message count in the title when a column in message list is sorted on inbox.

Related files: steps/mail/func.inc:L628 js/app.js:L3849

Can you take a look please?