GPO not refreshing Internet Security Zone settings

[NS]

Something is changing the reg key
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet
Settings\Zones\3\1803 from the desried value of 0 to 3 which prevents IE
Downloads.
I have a GPO that should be setting this key value to 0 but the only way i
can achieve this is by using the command gpupdate /force /target:user. A
logoff/logon or reboot does not overwrite the registry setting. Is this a bug
?

Ideally i'd like to identify what is changing the key in the first place,
any pointers on how to achieve this would also be much appreciated.

 

[PA Bear [MS MVP]]

One or more options/settings in an ever-growing number of third-party
applications may be disallowing the change(s) from "sticking". These include
but are not limited to Ad-aware's Ad-Watch, Spybot Tea Timer,
SpywareBlaster, SpySweeper, Spyware Doctor, CounterSpy, AVG Anti-Spyware,
Norton AntiVirus, McAfee VirusScan and/or Antispyware, NOD32, and Zone Alarm
(Free, Pro, & Security Suite).

 

[NS]

McAfee VS I do have on the PC but since the PC receives the same AV policies
as 100 + machines in the same department I think i can rule it out. I'm only
seeing my issue on a select few machines & at random times. I will of course
stop McAfee serivices for a period of time & monitor. A quick audit of the
machine doesn't show up any unusual programs like those you mention.

What tools could i use to capture the application changing the key ?

Still need to find out why a logoff/logon or reboot does re-inforce the GPO
settings but using the command line does?

 

[NS]

Can any one else help me determine why GPO is not refreshing settings unless
I manually refresh using the force option via command line ?