For the past 3 or 4 weeks, i am using a new MacBook Pro with Mountain Lion. iTunes is 11.1.3 (8). It replaced a 5 year old MacBook that is barely limping along. It's been a pretty big adjustment for me because i was on Snow Leopard, was using Rosetta dependent programs, particularly Eudora since 1995, adjusting to Apple Mail, big difference, i am gradually trying to get my new system to do all the functions the old system would do.
Tonight, i finally got around to dragging my music files onto the new computer. I have been using AirTunes on my old computer. Tonight l found out that AirTunes is now AirPlay and is different in some ways. I went to the sound preferences and selected the Airplay device. Through iTunes, sound came from the external speakers briefly and then cut out. i tried to work with it and at some point, music played continuously through the external speakers. After about an hour, i quit iTunes. Later when i started iTunes back up, AirPlay would not work consistently. It's what i would call buggy. The music would cut out again, more off than on. At one point, the external speakers could not be selected in the Sound preferences. it defaulted to internal speakers and when i clicked on external speakers option, it wouldn't stay on, it kept going automatically back to internal speakers. Then, soon after that, external speakers disappeared from the Sound preferences output list and only internal speakers were listed. After some rebooting and permission repairs, external speakers returned as an option but continued to lose audio output almost continuously. Virtually continuously.
During this process, i noticed my computer became much slowed down. It has been very fast, opening webpages and everything on it happens immediately, usually. that has been the happiest thing about the new computer, really fast and smooth. But after trying to use iTunes wiith AirPlay, the whole computer slowed down. The processing is slowed down.
Until i read this thread, i didn't know that repairing permissions isn't helpful unless you get a message saying you don't have permission to do something. In fact, repairing permissions is the only thing i know to try when something is not working right, other than rebooting, not that it necessarily has made any difference. So, i repaired permissions. In the permissions that were repaired there were seemingly hundreds of iTunes contents nib repairs
e.g. Repaired “Applications/iTunes.app/Contents/Resources/zh_CN.lproj/InfoDialogMultipleInfoV iew.nib”
I repaired permissions and rebooted 3 or 4 times, each time testing my computer to see if the quickness of the processor came back. It seemed a little better, but still sluggish compared to how it was before trying to use AirPlay. I have no idea whether repairing permissions had anything to do with any of this, especially after reading this thread. I repaired permissions about a week ago and none of those iTunes repairs were there, but that would be because the files weren't there til tonight. I guess the computer is trying to make sense out of all the new files. At any rate, none of the "repairs" repaired anything--each time, all the repaired permissions were repaired again--and again, apparently for the reasons reported in this thread.
Whether any of this is related to AirPlay not working and having bugs, followed by the computer processor slowing down, i don't know.
I would like to ask, since repairing permissions doesn't seem related to the problems i'm having with iTunes and/or AirPlay, are there other kinds of repairs i can do to restore the speed of my computer? I wish i could uninstall and erase AirPlay since it doesn't work and may be screwing up my computer system. Is there a plist i can delete that might help? Or anything else?