Getting Gamin and imapd to work for real-time folder updates

[Hank]

Shupp Toaster installed a couple of weeks ago on a fresh install of
CentOS 5 2.6.18-164.11.1.el5PAE

I've read all the docs, I have the following set up in:
/usr/lib/courier-imap/etc/imapd

IDLE set in:

IMAP_CAPABILITY="IMAP4rev1 UIDPLUS CHILDREN NAMESPACE
THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA AUTH=CRAM-MD5 IDLE"

and...

IMAP_IDLE_TIMEOUT=60
IMAP_CHECK_ALL_FOLDERS=1
IMAP_USELOCKS=1
IMAP_ENHANCEDIDLE=1

And I have Gamin installed and running (it was installed and running
in CentOS before installing the toaster)
$ps ax|grep gam
4971 ? SN 0:00 /usr/libexec/gam_server

And I've stopped and re-started courier-imapd

And yet, my IMAP client - Thurnderbird on WinXP will not see any new
mail in any subfolders. The top folder seems to be working. Once I
click/open a folder, all the new mail appears.

And using the same client pointing to email accounts hosted on a Shupp
toaster I installed 5 years ago using SGI_FAM, this works perfectly
(real time folder updates). So I doubt it's the client.

What am I missing?

thanks,
-Hank