No need for old versiosn. Install the latest DX ver 12 program and you'll get a 2nd AH icon- a beta version icon. You click that one to fly with the beta version. If you no like, or have bug problems, go back to using the regular version. This way HTC can have folks report problems without them losing thier ability to play.
They reside side by side in the HTC/AH directory but the beta does not mess with your existing installalled version.
Westy