The machine 'SyC-Server' is already locked for a session (or

[Fridirik]

Hi,

In my HP Laptop ( Motherboard: Hewlett-Packard HP Pavilion dm4 Notebook PC / CPU: DualCore , 2779 MHz (28 x 99))
with Windows 7 32b (Windows 7 Ultimate 6.1.7601 Service Pack 1) recently installed (had to reinstall because I thought problem was Win7 64b)
Vbox fresh new (4.3.6 r91406):

I had no problems on installation of windows XP on the vm.
Once I start virtualmachine, laptop keyboard and mouse stop working normally.... keyboard keys strange characters and mouse button doesn't answer normally... host key also does strange things. I loose control of vm and Win7 as well.
Only way to return to normal state is to reboot win7.
when click on vm icon I get this message:

Fallo al abrir una sesión para la máquina virtual SyC-Server.

The machine 'SyC-Server' is already locked for a session (or being unlocked).

Código Resultado: VBOX_E_INVALID_OBJECT_STATE (0x80BB0007)
Componente: Machine
Interfaz: IMachine {480cf695-2d8d-4256-9c7c-cce4184fa048}

Already tried everything OS and configuration wise.... Do you know if there is some bug with this HW?
Thanks.

Fridirik