If your using global coverage cloud maps you need to set them up to spherical projection and set the "Position" to the same as the planets centre, ie 0, -6.378e+006, 0. Leave the scalling as it is, ie 1, 1. That should do it.
Also if your far enough away there is not much need to use a cloud fractal, just plug the image map directly into the cloud layer.
Hope this helps
Richard