2006-09-25 : Detainment Spell prevents mana abilities of the enchanted creature from being activated.

2006-09-25 : Morph isn’t an activated ability, so Detainment Spell doesn’t prevent face-down creatures from being able to turn face up.

2006-09-25 : Responding to a creature’s activated ability being activated by moving Detainment Spell onto that creature won’t affect the ability that was just activated.