stereo_image_proc and V-rep: Don get the point cloud

hi, I create a model of a stereo camera in V-rep with tow vision sensors and publish the images in ROS. Then I use stereo_image_proc to create the disparity map and the point cloud. The disparity map works without problem, but I am no able to get the point cloud in the pointcloud2 topic. Does any one know what could be the problem? I can use image_view and I get the three image perfectly. I have also tried to change the parameters. My problem come with the pointCloud2 topic. I get the RGB part but not the XYZ. I am working with a camera created in the V-rep simulator (not with a real camera) and I think that the problem came from there. Thanks in advance, Fran