I am getting the exact same error after the latest update too. I'm running a Windows 98SE machine with Outlook 2000. I get the error message when I receive a new email, try to read a new email, and when I try to send an email. I'm assuming that the Avast program is not being able to scan the email. But I have no idea how to fix it. I'm open for suggestions too because I would like to get this fixed.
Thanks!
F1 Fan (go Kimi!)