VT-x usage detection clarification?

[xerces8foo]

With:
Windows 7 Po SP1 64 bit
VirtualBox 5.0.2
Intel i7-2640M

I noticed that VB gives the "VT-x is being used by another hypervisor.(VERR_VMX_IN_VMX_ROOT_MODE)" error if VirtualPC is running at the same time.
But if VMware Player is running (also in VT-x mode), VirtualBox does not complain and run its VMs just fine.
(that is VMware + VB, but not VPC)

The guests are 64 bit, except the VPC guest (VPC does not support 64 bit guests).

Is VMware's use of VT-x not a problem for VB? Or is it not detected? Something else?

Regards,
David

[Perryg]

Most hypervisors play well together with the exception of one. MS does not want you to play with anything else.

[xerces8foo]

Just an information: VMware Player works fine in VT mode while VPC is running (according to its settings and log:
vcpu-0| I120: Intel VT enabled.
vcpu-1| I120: Intel VT enabled.
)

[Perryg]

Then that is what you should use.