Cannot scan message body. This error just started today, but I don’t recall any recent updates.
Outlook 2007
Vista Business SP1
This is an old problem that was “fixed” a year ago in version 4.7 so I am not sure why you have this problem now. Perhaps one of the official avast team members could help here.
Reference :
http://forum.avast.com/index.php?topic=27756.0