Brenden
Thanks for your suggestion. That did not seem to solve my problem. I'll try to give some more details. What I have done to date is to deauthorize all computers and then authorized my mac-pro. I have iTunes open and signed in. If I click on Store in the top line, in the bottom field it gives me the option to Sign Out, View Account(my id) and Check for Available downloads.
If I select View Account a pop up opens that reads "Enter Password for (my itunes id)" When I input my password and click "view account" the progress bar shows accessing iTunes store. After about 10 seconds, another pop up window opens up and this one reads "Sign-in to view account information". I can confirm that I am already signed in. It says below that "If you have an Apple I, sign in with it here. If you have used the iTunes Store or ICloud for example, you have an Apple ID. There are 2 fields for data entry the first one Apple ID which already has my ID populated. The second if or my password. When I enter my password and click Sign In, it will wait about 5 seconds and then the same popup will return, no matter how many times I repeat this.
I have the same results if I try to make a purchase using iTunes on my mac. I can make purchases from my iPhone with no problem.
I have found that if I login to the app store on my mac I can view my account.
Is it possible that I need to delete iTunes and re install? A very important question before I do this, is will I loose my backups for my iPhone and iPad, ring tones etc? I assume that when I log into iTunes my library will be re established.
Again, thanks for your help! While not a game stopper this is annoying.
tckgator