This is what I got back from paypal. As far as I can see, everything is set up. We are approved, and I was running this live.
Hello Michael Andrews,
This is not an error message that would be getting returned from PayPal. If the shopping cart was connecting to PayPal and erroring out, you would be getting back a long error message, a short error message and a 5 digit error code. I checked your logs for the last 5 days and I do not see any API requests hitting your account. This sounds like a general error that your cart is giving. I would suggest checking with your cart provider to see what this specific error message means, or if they have logs that they can check to see what is causing the error or if they can verify your setup in the cart.
Sincerely,
Chad
Merchant Technical Support
PayPal, an eBay Company