New problem "next unread" (not sure how new)

[Jack <ostroffjh users sourceforge net>]

Hello all,

I think I started noticing this relatively recently - probably about  
the time (or shortly after) the recent set of updates related to  
threading.  (git head)  Most of the time I hit the "Next unread" button  
(on the toolbar) when all messages in the current mailbox are read, it  
does go to an unread message in the next mailbox with any uread  
messages.  I actually still haven't paid enough attention to confirm  
how it chooses the specific message.  However, sometimes (fairly  
consistent by mailbox, I think, but all my mailboxes are maildir  
(except inbox)) it goes to the message with the id number one less than  
the first unread message.  As we've discussed in the past, the message  
id ordering seems to be essentially random, but likely the order in  
which the messages are read when scanning (or reading) the directory.   
Is it possible there is an off-by-one thing going on?  I'd be more  
certain if it were more consistent.  The reason it's annoying is that  
due to the ordering - it sometimes chooses a message nowhere near the  
first unread, when ordered by date with JWZ threading.

Thanks for any thoughts.

Jack