Pushback

Hi,In advance of the tutorial I'm getting up to speed in Button Mode before going back to Voice ... And all's going very well too especially after noting certain issues will be fixed in SP1.But I sure would appreciate some input on a push-back problem I'm experiencing before I go re-installing everything, perhaps unnecessarily.I realise it's a more limited function in the Button Mode, but the big red arrows in the docs I find a little confusing - however, following the text instructions I have the Service Interphone Switch 'ON' on the OHD, the SVC button pushed in and the SVC amber annunciator lit on the Captain's radio, but when I push the GRD CALL switch on the OHD I don't really know what to expect (another panel with Grd Options?) but all I get is a squeak that has 'fail' written all over it. It would be nice if someone could point out that I am not setting up the Cap's Audio panel properly as everything else seems to be fine. So far anyway. Thanks in advance,Gareth