Host networking from virtualbox

[Bruce Marshall]

I'm trying to get virtual box to work and have everything set up (Win XP as a 
guest)  but can't get a host networking bridge set up.

I have read the VB user manual and done all the steps to set up  tap0 and br0 
on my gutsy box.

When selecting host inteface in VB for the networking,  on boot, I get a 
message:  


Unknown error creating VM (VERR_HOSTIF_INIT_FAILED).
VBox status code: -3100 (VERR_HOSTIF_INIT_FAILED).


Result Code: 
0x80004005
Component: 
Console
Interface: 
IConsole {1dea5c4b-0753-4193-b909-22330f64ec45}

which indicates a problem (I think) with the host interface.

Has anyone been successful get VB to do networking using a host interface?

Thanks.