Hi ... I bring that thread back up, as I almost get insane with the very same problem, meanwhile with Logic Pro 9.1.5 and Macos 10.7.2.
I have a song in 64 bit mode that hangs during launch, showing "searching....Channel EQ" but when I simply start the Logic application it says "searching....AUnetreceive", and I have to force quit. I had some success trashing all kinds of cashes and running Onyx, but the trouble keeps returning every day. And there's no easy quick fix (still I don't really know what exactly cures it, it seems to be a combination of things)
32 bit mode does the job but is no solution as I have much memory addressed.
repairing permissions seems to fix a lot of stuff which is AU / core audio related. But doesn't fix the problem.
so has anyone struggled through this and can tell me what to do? thanks Uli