Aegir Appliance installation gives Virtual Box network errors

Referenced Page: 
Aegir Virtual Appliance

hi chalet16, kimplot

thanks for making this virtual appliance

can you help ? I am getting error messages from VirtualBox 4 when I try to start the Aegir Virtual Appliance on a clean install of Ubuntu Lucid

Failed to open a session for the virtual machine Aegir.
Failed to open/create the internal network 'HostInterfaceNetworking-wlan0' (VERR_INTNET_FLT_IF_NOT_FOUND).
Failed to attach the network LUN (VERR_INTNET_FLT_IF_NOT_FOUND).
Unknown error creating VM (VERR_INTNET_FLT_IF_NOT_FOUND).

Result Code:
NS_ERROR_FAILURE (0x80004005)
IConsole {515e8e8d-f932-4d8e-9f32-79a52aead882}