declination vs latitude: same reults obtained

I have put a couple of antennas in the South (-90) and want to compare a couple of options: declination of the object at -90 and declination at 90. Likewise, H0 and H1 are maximased .....the problem is that in both cases I do see the same dirty image and dirty beam. Is that correct? My assumption is that we should not be able to "see" anything in the north from the south! is the program able to recognise this or I am doing anything wrong?
thanks!