Then what I do is move the time slider forward and then return it to frame 0 and more particles appear. I continue doing so and more particles appear but it reaches a point where no more particles are displayed, as if it had a limit. This also happened in another project but I got to have them all finally (but I think the program stopped being stubborn and it was nothing I did, I'm not sure). The problem is not only in the viewer, but also when I render this limited amount of particles are displayed.
It has nothing to do with the Thinking Particles particle limit in the settings, as the number is like 100000 or something huge like that. So I don't know what can I tweak... I'm affraid it is more likely a problem with the program... any ideas?