No paypal hasn't changed anything that should effect you. She may be using bad credit card or date syntax. You would have to add debug code to the failure page to find out more.
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.