Paypal "Payment Information" Not Working

The short version: When I try to check out using the Paypal Express checkout, it gives me a blank screen on the "Payment Information" screen. When I click "Continue Checkout" on the blank screen, it then displays "There was a problem connecting to PayPal. Please try again.
There was a problem connecting to PayPal to setup your purchase. Please try again."

The long version:
I'm using WP 3.2.1 and MarketPress version 2.2. I selected Paypal Express as the payment gateway and entered in the appropriate information including the requested API credentials. I left it in sandbox mode and gave it a test drive. It works fine up through the Shipping Address screen and when I click "Continue Checkout" it takes me to a blank "Payment Information" screen. That's when I get what is happening in the short version above. It leaves me with that error message. I switched to "Live" and got the same results.

I've integrated PayPal into other systems in the past, just not on Wordpress or with this plugin. Was hoping it was be simple enough, but I should know better by now! :slight_smile: Any guidance is greatly appreciated.

Thanks - Chris