Avast is Internet Security ver120217-0
Spam filter is enabled - I even switched it off and back on again. It IS analysing my emails according to the antispam screen.
Yes Microsoft did install updates yesterday. Having checked the update history there was one for Outlook details as below the rest were Windows security updates
Update for Microsoft Office Outlook 2003 Junk Email Filter (KB2597968)
Installation date: 16/02/2012 07:42
Installation status: Successful
Update type: Important
This update provides the Junk E-mail Filter in Microsoft Office Outlook 2003 with a more current definition of which e-mail messages should be considered junk e-mail.
More information:
http://support.microsoft.com/kb/259796
8