We are aware of the problems running Playmaker in the Unity 3.5 beta, and will have an update out very soon.
We've been working with the 3.5 beta for a while, but Unity taking their beta public
forces us to get our update out a little quicker!
We're very excited about this update, with new features like drag and drop to add/move actions, DebugFlow to scrub through time, networking action, pathfinding actions and more!
Thanks for your patience as we finish up this update!