That's the only change I also observed. You have to use the Particle* p pointer when using it in the particles function...

Here's some code snippets
Code:
action particle_start // this can be a function as well
{
  ............................
  effect(particle_function, number_of_desired_particles, starting_position, initial_velocity);
}

function particle_function(PARTICLE* p) // this function is run by each and every particle
{
   // set the properties and the speed of the particles here
   ............................
   p.event = some_function;
}

function some_function(PARTICLE* P) // this (short) function tells the particles how to behave after they are emitted
{
  ............................
}


here's also some of dust particle thread. Maybe, you could get some idea on it.
particle

Cheers!