Well, apparently your picture size is 1280x460, and that width (depending on your monitor resolution) is pretty much an entire monitor's width worth of pixels. So, are you sure you're looking at the picture at 100% zoom, or did photoshop do the automatic scaling thing since the picture was too big? That might be the problem. Because the clouds themselves look right, but for a picture that's been zoomed out like crazy (i.e. a big picture).
