Paypal Error with non registed user MarketPress

I just did a test with a non registered user
these are the steps you can verify if they are correct.

- Loaded up website
- picked two of the free Digital downloads.
- Clicked on View Cart at the top of page.
- Clicked checkout
- everything looks good with total $0 and it gave me two options first is log in and check out, the other Checkout Now.
- I hit Checkout Now
- It changed top a page that just had Checkout and continue checkout button on it.
- Clicked continue checkout and got a pink error that said

There was a problem connecting to PayPal to setup your purchase. Please try again.
10525 - Invalid Data - This transaction cannot be processed. The amount to be charged is zero.

I looked for a manual check out option in Select Payment Gateway(s). (if I member correctly there was one)

What did I do or set up wrong?