Hello,
I bought GX last week and had same problem (win8 64). License manager showed nothing when i connected my GX. Reinstall didnt work. But I solved it. I just enabled compatibility mode (winxp sp3) for POD Farm 2. Then from POD Farm I run License manager, it run also in compatibility mode, and it found my GX and i could authorize it. When i disabled compatibility mode it didnt find it again, but device was authorized and POD Farm 2 was fully working. So everytime I want to use License manager I run it in winxp mode.
I hope it helps.