Problem connecting USB device in Windows XP and 8.1

[MestreBond]

I use Virtual Box 4.3 running on OSx Mavericks, I'm having great difficulty connecting to PBX intelbras, The error appears:

"
Failed to connect the USB device Intelbras S / A CDC Virtual COM [0100] to the virtual machine Windows XP 64.

USB device 'Intelbras S / A CDC Virtual COM' with UUID {08a54fdf-86e0-405e-89f2-be417778166f} is in use by someone else.

Result Code: NS_ERROR_FAILURE (0x80004005)
Component: HostUSBDevice

interface:
IHostUSBDevice {173b4b44-d268-4334-a00d-b6521c9a740a}
caller:
IConsole {8ab7c520-2442-4b66-8d74-4ff1e195d2b6}

"

I've read everything on this including forums and it still fails. Already deactivated USB 2.0 and nothing worked. Someone could help?