credit card checkout with paypal sandbox

From Canada using PS2:

When I use my credit card info or the dummy info to check out with a credit card using the PayPal sandbox API Credentials I get;

Transaction Not Completed
Your transaction could not be completed. Either your credit card information or billing address has problems and cannot be processed

Please return to checkout and try again.

should this work using the sandbox or will I have to wait until I have my Canadian Website Payments Pro account set up?

My sandbox dummy seller and buyer are both Canadian.

The express checkout works great but I need the Credit card only option also as PayPal does not give Canadian customers the option of checking out with credit card unless they apply for a PayPal account.

I really NEED to know if this can be customized to work from Canada before I put too much more effort into it?

Nancy