Why does iTunes want my Security Code when I have Store Credit? I have $10.00 next to my name in the iTunes screeen.

I click to buy "Surfin Safari" (by the Beach Boys) for $0.99.

I am then asked for the security code on my Credit Card.

Why?

Why can't it just take it from the iTunes gift card I put in?

GRRRRRrrrrrr.... Frustration!
Duh!

Just click 'None' for the credit card type.

Not totally intuitive, but I should have figure this out without a question...