20 May 2010, XP Pro SP3, IE8, Symantec Corporate client 8.0
The Symantec article updated 19 May 2010 worked:
On our systems the fix was the HKEY_Current_User solution:
HKEY_CURRENT_USER\Software\INTEL\LANDesk\VirusProtect6\CurrentVersion\Custom Tasks\Default Scan Options
For us it seems the latest Microsoft "update" messed w/ the Symantec registry entries. Note the date of the Symantec article, 19 May 2010. They were quick to suggest a fix to this mess. Kudos Symantec. M$, byte me.