I purchased the Xfrog Plants Tropical collection, ran the "xfrogcatalog100.exe" which installed the catalog into Forest Pack Pro.
When I went to use a plant for the first time it asked me for a location. It took a couple of tries (don't remember now which worked), and I'm able to add the plants to the Max scene, but the textures seem to be missing. The plants are sort of brown/grey. Not tropical green. (I have forest pack grass in my scene which is actually green, btw).
I'm using 3DS Max 2011 64-bit. Forest Pack Pro 4.0.3