Hi Andy, Thanx for your fast response. Maybe I can try setting up my MCU in logic control modus, currently set to mackie control, though it shouldn't matter. I was thingking maybe you can e-mail your logic preference's file, so i can load that file in my mac and adapt it to my setup? Maybe I do have a wrong setting, that i don't know about???? And how much ram do you have in your mac? What length of midi-cable do you have between your MCU and your Unitor8/AMT8? (in metric system if possible) thnx again ..., Marius