I'm guessing that since it is a USB capture device Windows in having the issues with it!(not signed)
Not sure why it won't work with PC Companion unless AHP or some other video software is running! (Two apps can't use the same USB capture card at the same time)
AHP access the VA12a on program start up Companion doesn't until you try to access the cams!
Not sure which version of PC Companion your running. 3.0.0.5 allows you to specify a USB capture device, previous versions only grabbed the first one Windows had installed!
X10 has not updated the SDK since the VA12A was released so it is possible there is something there as well!
The VA12A was built for AHP and Vanguard most likely why launching AHP fixes it!
Nice to hear Homdomination works for you I could never get it to see my CM15A
I don't have a VA12A to test so it looks like it is next on my list of devices to get!