There is a known issue with all the latest SVN (an PR1.0) that Pneuma does not work sometime. But this sometime appears to me as all the time since I've been unable to get it work a single time since I'm using it.
So I would like to know WHEN it worked for you. It at all. Like what was the map, the monster, PVP or not, where you standed (in the pneuma or the cell around), how far was the attacker, your class, etc.