Hi Jim,
This is a bug in the cloud rendering which is somewhat related to the horizon problem you might see if you put the camera within the clouds (even though that is not the case here). In other words, they will be fixed at the same time. It is a bug in the visibility ordering of objects, clouds and atmosphere, and is really a problem with objects obscured by dense cloud and fairly dense atmosphere.
This can be avoided by increasing the altitude of the clouds just enough so that they don't obscure the top of the mountains. In many situations you can get away with it, but unfortunately apparently not here (probably due to the thick atmosphere below the cloud).
Matt