If you were to have a summon swallow an enemy with SR, cast a spell like Icy Prison on the summon, then dismiss it, would the enemy automatically be in the Icy Prison or would you still need to overcome their SR?
PRD sez: "Spell resistance can protect a creature from a spell that's already been cast. Check spell resistance when the creature is first affected by the spell."
Sounds like the creature with SR gets the benefit of the SR when the summoned creature that swallowed them disappears.