Problems with $folder with Courier 0.45.1 and Mutt 1.5.6

[Pete Toscano <pete-mutt@xxxxxxxxxxxxxxxx>]

I recently upgraded our mailserver from Courier 0.44.2 to 0.45.1.
I'm using mutt 1.5.6 as my MUA and connect to the Courier IMAP server
via IMAPS.  In my mutt config, I define $folder as
"imaps://pete@server/INBOX".  With this definition and Courier 0.44.2,
'=' worked as a perfect alias for the contents of $folder.  Since I
upgraded to 0.45.1 (without changing any mutt config), whenever I try to
change to my inbox by hitting "c" then "=", I get the following error
message: "Mailbox does not exist, or must be subscribed to."  However,
all my other references to "=" in other folders works fine (such as
"=foo" in defining "mailboxes"). 
                                                                                
          
Any idea why this is and/or how to fix it?
                                                                                
          
Thanks,
pete

(I posted this to the courier users list a few days ago, but nobody was
able to help, so, since I wasn't sure which list would be more
applicable, I figured I'd try here.)