biff check broken w/multiple IMAP accounts?

[Ken Gunderson <kgunders@teamcool.net>]

Hello List:

I have several IMAP accounts.  I configured Wanderlust thusly to check
their inbox folders:

(setq wl-biff-check-folder-list
      '("%INBOX:acct1" "%INBOX:acct2" "%INBOX:acct3"))

This seems to sync these mailboxes at the specified interval. Sort of.
A couple issues:

1) While the number of unread messages is updated in folder view, the
number for new messages is not, e.g.:

Before check: INBOX:acct1:0:5:20

After check: %INBOX:acct1:0:6:21

2) It does not update new mail status icon on the modeline, nor beep.
This leads me to suspect the notify-hook may well not be being
executed.

3) Clicking on the modeline mail icon updates as outlined above, but
still reports "No mail".

4) Everything works as expected if I pare the folder list back to a
single INBOX, i.e. modeline icon changes and folder view will update
new message count, rather than just unread message count.

Some magic I'm missing here?  Or would this be a bug?

TIA-- Ken