2checkout error upon return

I've been through the manual several times and have reinstalled and configured the gateway multiple times. Everything seems fine except I keep getting the following error: "Sorry no response from 2Checkout for your payment. Please check your email and status later." when testing it in Demo Mode.

What are common causes for this and what other diagnostic information can I gather to help track down the source of the error?

Thanks

Noticed that 2checkout has a revised INS message protocol. Was the plugin upgraded to match?

Good Golly Gracious!

Somehow I missed reading the section that stated that the INS does not work in demo mode.

You might want to put that in bolder letters in the manual.

Problem resolved.