iTunes always makes me sign in twice
When purchasing content on iTunes or downloading purchased content (e.g., from season pass), I am prompted to sign in--twice. I get the dialog to sign in, I enter correct username and password, then I get the dialog again, enter correct username and password again, and then it goes through. I'm not mistyping my username/password as this has been happening consistently for months. I am on latest iTunes (v10), but same problem occurred on prior versions for at least several months. I'm also on latest OS X. Any ideas why it prompts me twice? I searched these forums and saw other people having similar problems, but didn't see any answers.
iMac late 2009, Mac OS X (10.6.4), iTunes 10