Please ensure you are selecting and adjusting the object in the elevation.

The settings must be like this

The result will be like this

Trees should display and print correctly both in 3D view and in elevation. The visualization problem you are referring, are documented on our website (FAQ) and they are related with Revit. The way to deal with it, for the moment (and the current revit version on the moment I am writting is 2014), is to override the transparency to 1%. Common sense says that 0% transparency should be opaque, but until today Revit that does not seem to be working that way. 

I added some of your trees which I just purchased to a Revit 2014 model and they are doing really weird things in elevation and 3d view - cer model elements are showing through the trees.See images below.