I turns out that apparently either the 1010 driver or the LAP for X midi driver isn't completely up to snuff in terms of CoreAudio spec compliance. I don't know which one was which, but here's what's worked for me. I don't use the Midi port on my 1010 (all my midi is via a AMT8). So: How to get LAP 5.3 and a Delta 1010 to play nice. 1) Install the Delta 1010 for OSX drivers (get from the Midiman site) 2) Go to Library/Core Audio/Midi Drivers 3) Get info on the "DeltaMidiDriver.plugin" folder. Change the owner from system to your user name. 4) Drag the DeltaMidiDriver.plugin folder out onto the desktop (or someplace else, just get it out of the library folder 5) Install LAP 5.3 6) Open the Audio Midi Setup (in the utils folder in Applications). 7) Click on the Midi tab. If you see a AMT8 or Unitor8 sitting there, you're home free. Done deal. 8) Launch LAP and crank away. Environment Tweezes I diddled my autoload a bit. 1) Open old 9.x Autoload. Saved in the 5.3 for X LAP folder. 2) Turn off any references to old VST plugs (won't crash or anything, but LAP will complain about them each time you launch until you do so. 3) Rearrange your screen sets to accomodate the dock then lock them back down. In my case I just had to resize my track window a bit. 4) Substitute any default VST plugs with the closest LAP native equiv. 5) Save. Took about 15 minutes once I knew what to do. I must thank a friend for pointing me in the right direction.