yes … everything is checked … all layers are 3d layers and accept shadows is turned on …
try it out by yourself guys … put 3 layers along the z axis (with space between them of course) and put a spotlight with small cone angle in front of the first one so that it just hits the middle of layer … the light illuminates all 3 layers …
if you activate the shadows the illumination becomes darker … but the light is still shining through …