I found this in UserInterfacePositioner.py :

def set3DZnorm(configElement):
if SystemInfo["CanChange3DOsd"] and getBoxType() not in ('spycat'):
print '[UserInterfacePositioner] Setting 3D depth:',configElement.value
f = open("/proc/stb/fb/znorm", "w")
f.write('%d' % int(configElement.value))
f.close()
config.osd.threeDznorm.addNotifier(set3DZnorm)

if I made a patch for this and I build, the image boot ?