Add me to the list of people with this problem.
I have followed all of Apple's suggestions for fixing this problem (changing user control in Windows 7, deleting SC folder, even deauthorizing and re-authorizing the machine), and I still get this error about the "apps" when I first try to sync. I get the error everytime i have re-started iTunes and plug-in my iPhone for the first time.
Following someone else's luck, I am downloading iTunes to do a re-install. If this doesn't fix it, we'll have to wait for an iTunes update I guess.
Apple's servers are having some trouble too - I have received 2 emails from Apple informing me that a purchase was made using my apple ID from a computer they did not recognize (I made the purchases, so I'm not worried), but this shows that Apple is having some serious issues with their iTunes Store / Apple IDs.
I'll let you guys know if I discover anything new.
(for some reason I cannot edit my previous post)
REINSTALLING ITUNES FIXED IT!
Download iTunes directly from apple (www.apple.com/itunes/) and when you run the installer select the REPAIR option. Restart your computer, and (hopefully) it should not generate the error.
Hope more people have luck with the reinstall!
I have the same problem. Here is what I have learned:
All your content -apps, movies, songs- is tagged to a specific iTunes account. The account name is visible on the song or app by CTRL-clicking the item and selecting Get Info. IN the Summary you'll see the iTunes account used to buy it and the owner's name.
A while back, Apple forced iTunes users who had simple user names like "JohnDoe" to establish new user names based on an e-mail so they could have easy audit and a unique idenitfier per user. So "JohnDoe" became "JohnDoe@mac.com" for example.
The probelm is your old iTune content still has the old tag on the songs so now when you Authorize, it sees John Doe@mac.com, authorizes that music, but when it sees the JohnDoe tags on your songs it sees that is illegitimate. And with the new DRM in iTunes 10.5 it pulls the content off your iPhone or iPod. In fact you will actually get flagged for the old JohnDoe username when you authorize, but it will be rejected since Apple doesn't accept that username format. Ironic.
So you have a closed loop.
The Apple store folks tell me there is no fix for this. Either through iTunes or the Apple store. The "fix" is to repurchase all that content under your new user name. for me that means several hundred songs. I've already rebought $35 worth of apps just to kill the annoyance. I'm not ready to fork over $600 to Apple since they are taking me hostage and I LEGALLY OWN THE MUSIC AND APPLE HAS RECORDS OF THE PURCHASE.
Apple needs to fix this since they are s&*$ing their customers now. Wish I had better news.
Seems that's always Apple's 'fix'. Just buy it again. That's wrong at every level. I am having a big problem with Apple's ethics these days. They dont' take responsibilty for their own mistakes, and they put the burdens on other. Looks like Steve Jobs' ethics (or lack thereof) magically live on. (And before I'm attacked for that, I admit Steve Jobs was a visionary and his idea of the look and feel of product, as well as functionality, was ahead of it's time. However, his arrogance stopped him from ever admitting a mistake.)
Here's a somewhat related issue - we have a HUGE amount of content we bought from Apple over the past 11 years. Well, we recently invested in a number of Sonos speakers for our home, and we're loving the system. HOWEVER, it won't play many of the songs we own because of constraints Apple's put on the music. They removed most of the constraints in 2007, but they tell you the only real way to un-do this mess is to re-purchase it. We're not going to do that.
The workaround? You have to burn the existing iTunes music to a CD, then zilch your old music, then re-rip. This takes a TON of time and resources!!!!!
I'm often fed up with Apple 'techs' because I know more about their file systems than they do. Apple is intent on making this thing of theirs so easy for users, but the fact is, they've just tried to keep users stupid. In the process, they've kept their own techs techs stupid as well. I can't tell you how many techs I've talked to in the past who have no clue what their own file system is like.
Well, that's my Apple Screed duJour.
If you have a apple acount this worked for me.
1. Click iTunes Store in the menu on iTunes.
2. If you're not signed in to the store, click the Account button, then enter your account name and password.
3. Click the Account button again, enter your password, and then click View Account.
4. In the Account Information window, click Deauthorize All.
P.S. You can only do this once per year so make sure you are doing it on the right computer and know what other computers you want to sync your device to if you decide to do so.