Hello, I am new to using Audio Unit plug-ins in Logic. I have Logic 9.1.5 running under OSX Lion 10.7.2. I just installed Ivory II Italian Grand on my MacBook Pro for use in Logic. I installed the "Ivory Items" on an external drive (because it is 7200 RPM and my internal drive is only 5400 RPM). Superficially, everything seemed to install OK. My iLok device is registered. It doesn't show up on the Mac desktop when I insert it, but when I run a system check it shows up in the USB area. When I open Logic, I find the Ivory Audio Unit where it is supposed to be under I/O -> AU Instruments -> Synthogy -> Ivory and seem to be able to load it on a track. The Synthogy window comes up fine. When I play a MIDI file on the Italian Grand track, there is no sound and the meter in the mixer does not register anything. The same MIDI file plays fine with an ordinary Logic instrument. Thank you for any help.