well, after much much pain. I figured it out. The only way this combination works is if you downgrade to MAC OS 10.4.9, either install a previous version and use the combo updater, or if you have 10.4.9 installer, use it and then use the combo updater (always use the latest combo updater for 10.4.9) Logic Pro 8 works using TDM and DTDM if you have 10.4.9, Protools 7.3.1 cs5, and Quicktime 7.3.x To anyone who thinks that you need coreaudio 7.4 to make this happen, this is not correct. PT 7.4 is not compatible with Logic TDM yet, i repeat, 7.4 does not work! Another important point, is that as soon as you install 7.3.1 cs5, and quick time 7.3, pro tools will stop working. You will get the icon bouncing for a couple of seconds and then die. You need to go to the digidesign website and download the prebinding fix script that corrects this problem. Always install protools first, test it, and then proceed to install logic. If pro tools does not work, repair permissions, delete all pt prefernces and delete digidesign databases. reboot. if this does not help, perform a clean uninstall of pro tools, re-install and run prebinding script. once pt is up and running, install logic. Good Luck. magia100