Group Policy Preferences File Association on older Clients

I have a GPP for file association aka "open with". It works as expected on Server2008/Win7 but does nothing on Server2003/WinXP that has both the GPP Client KB943729 and GPP hotfix KB982051 installed. I have tested it on one target of each type.

The GPO also contains the GPP debug logging for "folder options", however on the older clients, the log path is created, but no log file is written.

The GPO is linked to the User OU for the folder options, and to the computer OU for the debug options. GPResult shows the GPO is being applied to the computer & the user. Looking for any ideas on why this works for the newer OS, but not on older OS's where GPP support has been installed. Thanks.

Computer Configuration (Enabled)
Policies
Administrative Templates
Policy definitions (ADMX files) retrieved from the central store.System/Group Policy/Logging and tracing
Policy Setting Comment 
Configure Folders preference logging and tracing Enabled  
Event logging Warnings and Errors 
Tracing Off 
User trace %COMMONAPPDATA%\GroupPolicy\Preference\Trace\User.log 
Computer trace %COMMONAPPDATA%\GroupPolicy\Preference\Trace\Computer.log 
Planning trace %COMMONAPPDATA%\GroupPolicy\Preference\Trace\Planning.log 
Maximum size of trace file (KB) 1024 


User Configuration (Enabled)
Preferences
Control Panel Settings
Folder Options
Open With (Extension: pl, Program: N:\Perl\5.10.1\bin\perl.exe %1 %*)
pl (Order: 1)
General
Action Update 
PropertiesFile Extension pl 
Associated Program N:\Perl\5.10.1\bin\perl.exe %1 %* 
Set as default Enabled