two virtual machine running with vt-x enabled

[davidef1986]

Hi, I was unable to submit a bug report so I'm posting here.
I'm running vbox 2.1.4 (upgraded from previous releases) on a ubuntu 8.10 32bit. I configure some virtual machine and I have enable the intel vt-x on some of them, afaik i can only run 1 vm with that technology enabled. anyway atm I can run 2 vm at the same time with vt-x enable as confirmed by the gui. This is strange but there is also something worse, if I disable on one of them the vt-x technology vbox doesn't let me boot that machine saying "An active VM already uses Intel VT-x hardware acceleration. It is not allowed to simultaneously use software virtualization." but I have just disable it in the options !!!
So is this technology really used ?? which machine is using it ??
You can fine the 2 logs of the two machine running at the same time here: first (xp) - second (ubuntu)

[TrevorPH]

So is this technology really used ??

The rule is: if one machine is using it then all of them have to.