Like many people, I have been trying to access the new iTunes Music Service today, and have been having problems getting connected. I tried to enable 1-click ordering, and Apple kept responding that there is a problem, to try again later. So I do.
But iTunes keeps reporing that there is a problem and to try again later, as it has been saying with many other "pages" on the site. So I keep trying every 5-10 minutes.
My bank calls me a few minutes ago, tells me that Apple has tried to do something with the account 16 times, and wants to know if our card got stolen.
[Update: it works now. Yay, Apple!]