I installed Office 2007 on my Windows Vista system as soon as it became
available, after completely removing Office 2003.  I use Outlook in
non-cached mode, so everything (e-mail messages, folders, tasks, an calendar)
was immediately available from my mailbox on our Exchange 2003 server.  Then,
a couple of weeks ago, I started missing due dates on various tasks and
arriving late for meetings, for which I had not received reminders.  In fact,
I have not recevied a single reminder for a single appointment or task in
weeks.  I have checked, and every item has the "Send Reminder" box checked.  
The default reminder time in Outlook is set to 8:00 AM.  I've now gotten in
the habit of checking my tasks every couple of days, but its's really
irritating to see tasks overdue, marked in red, and yet no reminder was
received.  Any ideas on what is happening, or how to fix it?

Thanks in advance

David