Magic Implements, Crits and Attacks that Don't Do Damage

[the Jester]

If I score a critical hit with cause fear (or some other power that doesn't do damage) with a holy symbol +1 ("Critical: +1d6 damage per plus"), does it deal 1d6 damage even though cause fear doesn't normally deal damage at all?

This exact situation came up tonight. I ruled that it would deal the damage as an 'on-the-spot, keep 'er moving' ruling, but would like to gather opinions.

 

[Psybuster]

No damage. See the third paragraph in PHB 225 of the Critical section.

"An attack that does not deal damage still does not deal damage on a critical hit."