1. Added one item to my cart for $25.00
2. Tried to submit payment using credit card 4111111111111111
3. Payment failed
4. Went to view orders and saw order was listed as pending
5. Clicked Process Card button
6. Got failure message
7. Edited card using the credit card in my Sandbox account on PayPal - 4972904295975980
8. Saved and then amount owed magically doubled to $50.00
9. Tried to pay with Process Card again and got following error message:

warning: Invalid argument supplied for foreach() in /home/.preacher/[purposely removed path]/sites/all/modules/ubercart/payment/uc_paypal/uc_paypal.module on line 1307.
Payment failed.

Error: This transaction cannot be processed. The amount to be charged is zero.
Address: An unknown error occurred.
CVV2: Not checked