Just hit a bizarre strangeness: APPEND timing out

[John Wiegley]

I just updated to Nicholas' latest next branch today, and now I'm seeing this:

--8<---------------cut here---------------start------------->8---
Copy message 407239 IMAP[[Gmail]/All Mail] -> MappedIMAP[[Gmail].All Mail]
Deleting flag S from 1 messages on [Gmail].All Mail
Copy message -1 MappedIMAP[[Gmail].All Mail] -> IMAP[[Gmail]/All Mail]
ERROR [<InstanceLimitedThread(Copy message -1 from [Gmail].All Mail, started daemon 4655943680)>]: command: APPEND => no response after 60.0 secs
ERROR [<InstanceLimitedThread(Copy message -1 from [Gmail].All Mail, started daemon 4655943680)>]: command: APPEND => no response after 60.0 secs
ERROR [<InstanceLimitedThread(Copy message -1 from [Gmail].All Mail, started daemon 4655943680)>]: command: APPEND => no response after 60.0 secs
--8<---------------cut here---------------end--------------->8---

It never finishes copying this one message.  What can I do to cure this?

Thanks,
  John