Sorry to revisit this problem but I still cannot get Logic to fully boot after upgrading to Tiger. This is the situation thus far: - I did and upgrade to 10.4 (not an archive or clean install) - all other apps seem to behave fine so far except for Logic Pro 7.01 (don't have 7.1 yet) - The Logic Splash screen indicates that all it fine until it gets to "Initializing CoreAudio" - It stays here indefinitely – weeks if I just leave it! - I downloaded the ProAppRuntime.dmg from the apple site and installed it several times – no change in behaviour. - I moved my plugin components directory temporarily to the desktop – no change! - if I hold down the control key during the boot process, it will ask me if it should start coreaudio. - if I say "No", logic will come up fine but without any audio capabilities. - when it does comes up I go into audio drivers and change everything to the built in audio drivers and reboot - the same thing happens. I have the following questions about this: - It is obviously something to do with CoreAudio. Do I have to do anything specifically to enable the new version of this component? - I have been operating fine with only 512MB of memory. Could this be the cause of the problem? - some people on this list have referred to two different ProAppRuntime downloads. How do I make sure that I have installed the right one/ - Is there any way to uninstall Tiger? Given my current situation, I'd rather just go back to the way I was before. - has any body else had the problem with the stuck "Initializing CoreAudio" that I described? Thanks for any help - I'm still stuck Naim