1) Not all of your products may have weights. All real-time shipping quotes are based on weight of the shippment. Add weights to any products that lack them by editing their attributes under Manage Products.
2) Be sure to complete Shipping Origin Settings (Realtime) at the bottom of the Shipping Management page in the admin area of the cart. To get a quote the cart sends over to / from zip code along with weight to the real-time shipping provider.
If you are still having issues, you may want to check with your hosting company and make sure they have cURL enabled in their hosting enviroment.
Note: Shipping prices added to the product under its attributes superscede that of the global realtime shipping method calculations.
