Particle problem

Hi again! I'm having other problem with my racing game. I created a PNG file to the tire particle emitter and one for the precipitation emitter. The tire emitter particle was working fine until I started using TGE 1.4, and now appears only a square where it was supposed to be the transparent image of the particle; and the same thing happens with the raindrop image for the precipitation. Is this really a problem with the TGE 1.4, or something eles? I have changed nothing in the code but the tire particle (that was working fine in TGE 1.3), and the raindrop I started using only now in TGE 1.4. If someone knows what to do, I'll be thankful.