This is my setup: Windows8 Pro 64 / FSX De Luxe SP2 / FSC9.3.HF_1 Build 04-August-2013 / FSCDBM 9.3 NET Build 26-June-2013.
I can't set the path for the Google Earth flightplan files: In the window "Save" there is a box to be ticked for "Google Earth". I have ticked it. In the window "Paths" there is no Google Earth in the Name column, and I can't save a path for Google Earth flightplans. (In the folder column these names are listed: FS Commander, Flight Simulator X, FSX Flight Plans, Squawk Box, IVAO Ivap v2, Radar Contact, FS Inn, Project Magenta, X-Plane and AS-Airbus X Ext, all with Folder paths.
I have been meticulous in checking that there really is a googlearth.exe file in the library chosen. The googleearth.exe file is installed in C:/Program (86)/Google/GoogleEarth/client.