The wiki is vague and so are the options of the plug-in.
Also, does Activehome Pro and Vox need to be on the same machine?
Nice to meet you too.
http://voxcommando.com/mediawiki/index.php?title=X10
You need a CM15A (as far as I know) and you must install the X10 transceiver and the ActivehomePro SDK on the same machine as VC since it is a USB device (not a network device). ActiveHomePro does not need to be running though, it is enough to have the SDK installed.