A recent update results in the Checkout page not allowing a customer to enter their shipping zipcode so tax and shipping is not calculated. There used to be a box for that information, but it has gone away. I don't collect any other user information at the time of checkout since I only accept paypal and it is all captured there.
"Calculate Shipping Price
Please specify shipping location below to calculate your shipping costs"
Even though I have used this program for 2 years, I am a novice user.