VM window should not be brought to front when it becomes active in full-screen mode

[Donuts]

Using VirtualBox 4.3.28 on Lubuntu 14.10 x86-64 host.

I have the window manager (Openbox) configured so the window under the mouse pointer is automatically activated, but not brought to the front, when the pointer moves over it. (Clicking in a window does bring it to the front.)

That works fine with a VirtualBox VM which isn't in full-screen mode. However when a VM is in full-screen mode, the VM window is brought to the front as soon as it becomes active, even though it has not been clicked in.

That's quite annoying if I have Alt-Tabbed out of the VM and am using other programs, with the VM window appearing behind the other program windows. As I move the mouse pointer from one other program window to another, as it passes over part of the VM window, the VM window is brought to the front, obscuring the other program windows.

I think a better behaviour would be to only bring the VM window to the front when the user clicks in it.