I am in the process of converting an iPhone game to iPad. Everything went relatively well with the exception of one problem:
Centers of particle textures are positioned in the lower left corner of the particle rectangle instead of in the center. Also, the displayed texture size is smaller than the particle rectangle. My particle system is a modification of one the classes from CCParticleExamples. If I don't supply the texture, the particles are rendered as white squares with the correct position and size. As soon as I provide a texture from a PNG file, each particle gets smaller and moves to the lower left corner of the area previously occupied by the corresponding white square.
I was wondering if anybody else ran into the same problem. I am not sure if the rendering would be different on the physical device - I don't have an iPad yet.