Pete,
The OPswat module is preloaded in the server then pushed down to the clients anytime the version number changes. Each revision brings additional supported av's as well as fixes comatibily bugs. In 4.8.2 and higher the opswat module (shown in the CCA Console as Compliance Module) can be upgraded indepenantly of client version, and if the cam has internet access you can even allow the compliance module to auto upgrade if you so desire.
