Email headers not showing on initial load in 1.7-rc4

[ehymel]

I recently updated from version 1.7-beta2 to 1.7-rc4. The problem below has now appeared:

When I first load ANY new unread message, all images in the message are blocked, as expected. However all email headers (From, To, ReplyTo, Date) are also missing (see screenshot). If I click off of the message then return to the new message, now all headers are correctly displayed. If I have previoulsy "allowed all from <email address>" then I see all message images (as expected) or I have the additional button of "Always allow from <email address>" (also as expected).

So, it's just the initial load of any new unread message. I'm not sure which version this problem appeared between beta2 and rc4.