Here is a better way to do this without enabling ALL plugins by default.
The proper GPO to resolve the issue is:
USER CONFIG/POLICIES/ADMIN TEMPLATES/WINDOWS COMPONENTS/INTERNET EXPLORER/SECURITY FEATURES/ADDON MANAGEMENT
Use the Option ADD-ON LIST
Add the CLSID of the browser helper object and a value of '1' to enable it by default.
Name: Symantec Intrusion Prevention
Publisher: Symantec Corporation
Type: Browser Helper Object
Version: 9.8.2.0
File date:
Date last accessed: Today, July 26, 2011, 2:49 PM
Class ID: {6D53EC84-6AAE-4787-AEEE-F4628F01010C}
Use count: 2
Block count: 3
File: IPSBHO.dll
Folder: C:\Program Files (x86)\Symantec\Symantec Endpoint Protection\12.1.671.4971.105\Bin\IPS