basic Bidule question

["Michael Peters" <mp@mpeters.de>]

I currently use Plogue Bidule on a Vista notebook with an Edirol UA-1EX
interface.

Here's the basic question (sorry if this is stupid): when I plug my guitar
into the interface, it can be heard even without any application running -
it goes directly through. Now when I use Bidule, of course I want the sound
to be silent when I pull down all faders, but no matter what I do, the
original thru audio signal can always be heard. What can I do?

-Michael