[Evolution] evolution won't show email

["brad haack" <bradhaack fastmail us>]

Evolution just got flaky on me.  Actually I can't tell if it's evolution
or my email service, fastmail.  I use fastmail & an IMAP setup.  It's
been working fine, then last nite it won't show any of the emails in the
IMAP inbox.  It shows that there are 19 unread emails in the inbox.  I
can read the emails in my subfolders, like Junk & Trash.  No, I don't
have a filter set up.  
Any ideas on how to debug this?