The new mail icon and sound work sometimes but not always. Also sometimes the new mail icon will not go away after I have read all email. Sometimes simply waving the cursur over the icon makes it go away, but not always. Sometimes it stays on until I close and reopen thunderbird. Running 31.7.0 but it's been doing this for some time. Windows 7 sp1 + updates. Just now I sent an email to myself. After a few seconds the inbox folder showed 1 unread message, 5 or so seconds later the sound alert sounded, a few minutes now and still no icon. Waited 5 minutes and still no icon. Marked new email as read. Sent another email to myself, in a few seconds it showed up in the folder and the sound was immediate, a few seconds later the icon showed up.