Responding with the tesla account since I am working on it now
- unofficial ruling but still valid wrote:
- If your opponent chains "Magic Jammer" to your "Scapegoat" you may still perform Summons that turn, but if they chain "Imperial Order", then you may not.
This one is pretty much the guideline for such cases, responding to your assumption that is. If you negate the activation of Pot of Duality then you may special summon. If you negate the effect of Pot of Duality you may not special summon.
However summons and card activations are nowhere close to each other. Even if your summon is negated the fact remains you attempted to special summon so you may not activate Pot of Duality in the same turn.
As a sidenote, if the activation of an effect which special summons is negated you may activate Pot of Duality in the same turn. If an effect which special summons is negated you may not. http://www.pojo.biz/board/showpost.php?p=20539209&postcount=289
~Al-Bhed