I’ve noticed this over the past couple of days, since the iTunes 10.6 upgrade. I don’t have the Radio library visible, and never use iTunes’ radio streaming service. But I’m seeing alerts like this constantly:
It seems to get stuck, waiting for a response, as this displays for a long time. I know that iTunes’ radio tuning server was not responding for about a week before the 10.6 update, and the problem I’m seeing may be related to that.