[intrepid 8.10] mail-notification no longer notifies on new mail

[David M. Karr]

I've had "mail-notification --sm-disable" running for my gmail account 
for quite a while now, and it's been working perfectly fine.  When I 
have new unread mail in my Inbox, it notifies me in the notification area.

Starting several days ago, I stopped getting any notification in the 
notification area when I have new unread mail.  I've rebooted a couple 
of times during that span, but it made no difference.

What can I try that might help diagnose this?