iTunes 10.5.0.142 audio fix
I spent a majority of the day yesterday banging my head over this. I thought it was my equipment. Then I noticed that songs that i had Purchased from iTunes worked just fine. Well, sorry iTunes, there is no way that all 5000 of my songs were going to be or will ever be purchased from you. So, basically, I figured out that the common denominator in all of it was the new version of iTunes (10.5.0.142), tried reinstalling etc with no luck. I looked on iTunes to see if I could downgrade to the previous version 10.4.whatever, and couldn't find it there, so I researched and found a site called Old Apps and they had what I needed. Just go on there and do a search for iTunes, and a list of every old version of iTunes will come up.
Anyway, there you will find a listing of every old version of iTunes there is. I just downgraded to 10.4.1 and everything worked fine. One thing though. Before you do this, make sure you back up a copy of your iTunes library! I have a copy of my iPod content on an external hard drive, AND on my computer HD. Because when you try to open with the previous version 10.4 you will get an error message The file iTunes Library.itl cannot be read because it was created by a newer version of iTunes." When you get that message, one way to fix that ONLY IF YOU HAVE A BACK UP OF YOUR CONTENT is to just go into the "My Music" folder and delete everything that says iTunes in My Music except for the separate iPod content file that you backed up previously. (There are also other ways to fix this, just Google "how to fix itunes library.itl cannot be read because it was created by a newer version of itunes")
Then you can open up iTunes, and it will recreate that .itl file in the older version of iTunes. Then all you do is "add folder to library, and select your backed up iPod content, and you should be god to go. A good program I have for backing up my iPod straight to my computer which works really well, and is a lot quicker and easier than just doing it manually is TouchCopy11. My wife bought it back in 09 (when it was touchcopy9) and we still use it. I think there is a free 15 day trial, so that should be enough for you to do a one time iPod rip so you can store it on your computer.
Good Luck!