Edit draft button in IMAP Draft folder is not present

Hi,

I am running the latest available ThunderBird Portable and I am missing a features that I have previously used in other versions of ThunderBird.

When you select a message stored in a Drafts folder in an IMAP server, the message window showed an "Edit drafts..." button in the recipients area (the gray area), but now it is not showing that button.

Any clue?

Best regards.