[HODGEKINS]

Hi,
I was wondering if anyone could please help me. I am running pro tools L.E on a G5 twin 2ghz processors with a digi 002 desk. I have a Focusrite voice master pro (hardware vale box basicly). If i record straight through the focusrite into the back of the 002 there is no noise problems and its fine however i want to send out pre recorded audio out of the 002 through the focusrite and back into the 002, now when i do this there is a (electonical?) noise, this noise is always there being picked up by my monitor speakers but does not effect normal audio recording but when i come out of the 002 the focusrite is amplifiying the noise making me unable to use it. I have made sure that each unit only has one earth source so im pretty sure that its not an earth loop. If i wiggle my mouse the noise cooporates so im almost certain that its a computer noise. Nobody i talk to can help so if there is anyone outhere with any clues they would be amazing. cheers Rich.