We looked at this in a connect meeting, with a fresh install, the Authorize.net checkout was working.
Express Checkout was still failing due to the TotalPrice calculation not matching the Price that was being passed.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.