Vampires and positive Energy Channeling

[Gwiber]

A vampire beaten down to the point where it must assume Gaseous form and return to its resting place. How vulnerable to the Positive energy channel of a cleric is it? Or would that effect it at all by that point?

The vampire is at 0HP by that point.

[Weirdo]

Vampires wrote:

Additional damage dealt to a vampire forced into gaseous form has no effect.

Once the vampire is in Gaseous Form and at 0HP it cannot be hurt, though if it can't reach home (home is more than 9 miles away, it's trapped in a force effect, etc) it's destroyed.

Sunlight should work on a gaseous vampire, too, since that's a special weakness that instantly slays a vampire on round 2 rather than just dealing damage.

[Lifat]

Channeling positive energy will damage the vampire. But once it reaches 0 HP it becomes a gaseous cloud and no longer takes ANY damage, including positive energy.

To kill a vampire you must first stake it through it's heart, then cut of it's head and then annoint the head in holy water
OR
Exposing the vampire to sunlight (natural) for 2 consecutive rounds.
OR
Exposing the vampire to running water takes away 1/3 of it's hit points per round. If it reaches 0 HP by taking damage from the running water it is slain instead of turning into the gaseous cloud.