Cannot enable second monitor

[DSinapellido]

Hello, i'm from Spain but i have a basic level of english, so im going to write the message in my language and then try to translate it.

Estoy corriendo Virtualbox 5.0.8 en Windows 10 (Actualizado hoy 28/11/15). Tengo montada una máquina virtual con Archlinux a la que le tengo asignados 2 monitores. Pero cuando inicio sólo carga uno de ellos. Cuando voy al menú de arriba, y abro el submenú de "View" abajo me salen "Virtual Screen 1" y "Virtual Screen 2". En la Nº1 me deja cambiar la resolucion, pero en la Nº 2 sólo me aparece "Enable", cuando hago click, no pasa nada (Aqui dejo un gif de gyazo <cant post urls>). Tengo actualmente 4 monitores, una GTX 760, un i7 3770 y 16GB RAM DDR3 1600 mhz en el Host; en el guest tengo asignado 8GB de RAM, 128mb de video y 2 monitores.

----------------------------

Im running Virtualbox 5.0.8 on Windows 10 (Updated today 28/11/15). I have mounted a Virtual Machine with Archlinux as guest, and i have assigned to it 2 screens. But when I load only one monitor loads. When i go to the menú (when the window manager is loaded) and i open the "View" menu, i have the sub-menus "Virtual Screen 1" and "virtual Screen 2". In the 1st I can change the resolution, but in the 2nd it only appears a "Enable" label and when i click on it nothing happens (Here a gyazo gif with it <cant post urls>). In the host i have 4 screens, a GTX 760, i7 and 16GB RAM. In the guest i assigned 8GB of RAM, 128mb of VRAM and 2 virtual screens; installed Archlinux completly updated with all the virtual box guest additions, xfce-4 with Awesome as windows manager.