I have a reoccuring problem with AE hanging up on startup. It seems to stop right when the program is going through the various folders that it is scanning and freezes up right when it gets to "Scanning Folder: 32_64bit". I have installed the Mac OS X 10.6.4 combo updater with no real improvement in it being able to get through start up. I did have a bit of luck when starting the program directly after I started Premier as an experiment when it opened in a snap. I am running it on a Mac 2 x3 GHz Dual Core Intel Xeon with 5 gigs of memory and as previously mentioned OS X 10.6.4. I have no firewalls running. Any suggestions?
No real idea, but this part here
I did have a bit of luck when starting the program directly after I started Premier as an experiment when it opened in a snap.
Would suggest the MediaCore or one of the services is busted. Since it works in Premiere, there may be a permission or other issue somewhere. Anyway, I would simply try to reinstall everything now that the update has been applied, but only after running the CS5 Clean Script/ Utility and manualyl deleting al linstalled files. Also run tools like OnyX to check your system status and fix potential problems.