Cloud transparency issue

Hello all,I've just downloaded a very nice set of "high definition" clouds by Pablo Diaz off of http://www.escuadron69.net/v20/foro/index.php?They are great looking, but I'm having problems when certain clouds pass in front of one another. It seems that certain clouds are more transparent than others, and the cloud appears behind a cloud in the distance, although it is passing by me faster (since it is closer to the aircraft). The effect is hard to describe, but it makes farther clouds look like they are closer than the clouds right near the aircraft. I'm chalking it up to a transparency issue, but was wondering if there was a solution?