A few days ago I started to download the new Xcode 5, but I canceled this update at nearly 40%.
Today I'm tried to download the update but it won't download. When I go to Mac Appstore, Updates it says "no updates available". I searched for Xcode in the Mac Appstore and on the Xcode app site there is the update button. But when I click on it Mac Appstore shows me up an dialog telling me
You have updates avaiable for other accounts. To update this application sign in to the account you used to purchase it.
I've never used another account to install Xcode. (Yes, I'm really sure.) I tried with log out and then sign in again in. I also tried the suggestion in this question: Why can't I install Xcode 4.4 on Mountain Lion?
Has anyone an idea?