It appears the plugin for Outlook mail is causing issues with outlook 2003. This is on an XP machine fully patched and up to date.
Selecting an email sometimes during mail downloading process crashes outlook 2003 (by crash I mean it totally closes and upon restart checks the mail files for error due to incorrect shutdown).
Sending the event to MS was reply the the AV caused the crash, and subsequent crashes indicated a DLL plugin was the culprit. A popup by Outlook requesting to remove or disable the plugin appeared. Disabling the plugin would not filter email for viruses. I have since been assessing this. If it persists I may have to uninstall Avast and try something else.