Forum:Torrential Tribute question

I heard that you can't activate torrential tribute if a monster is special summend with card effects like mother grizzly, mystic tomato etc. Is this true and is there a reason or is it just a general rule. And what other situations like this are there. For example: if I activate Emergency Teleport and special summon a monster can I activate trrential tribute?79.114.118.88 (talk) 19:45, August 7, 2010 (UTC)