In this post, Jmorri experienced trouble when installing the Add-On Pack with the new build 16.1.0.33. An error message reported that the Add-On Pack was "incompatible" with the new build.
To confirm the issue I attempted to install the Add-On Pack and I encountered the same results as Jmorri. The Add-On Pack would not install citing incompatibility issues with 16.1.0.33.
The solution which worked for me was as follows:
Navigate to: C:\Documents and Settings\All Users\Symantec Temporary Files.
Delete any AOP downloads located there. (Actually, I had a few other downloads there including a 2008 download which I also deleted.)
Once the files are deleted, open the main Norton interface.
Go to Settings > Parental and Privacy Controls then "Click here to install".
The Add-On Pack proceeded to install flawlessly.
I hope this may work for others who have experienced this issue.