Hello.
I think this is a bug in the Bitdefender update platform.
I installed Bitdefender 2012 Total security on my main PC at August 2011 launch. Bitdefender AVC HV driver was dated 07/2011.
Recently i installed Bitdefender 2012 Total security on another PC (fresh install) and i noticed the Bitdefender AVC HV driver version was newer and dated 11/2012.
So i uninstalled completly BD 2012 Total security on my main PC and i re-installed it. So driver Bitdefender AVC HV was updated correctly.
So i think that when a new build of Bitdefender is released through auto-update the Bitdefender system driver is not updated.