If you’re integrating iDevAffiliate with direct PayPal buynow/subscription buttons and you’re buttons are located in a WordPress created page, you may need the following WordPress plugin. Why? The code being used in your iDevAffiliate compatible Paypal button uses a snippet of PHP code. By default, WordPress doesn’t allow PHP code to be used in your pages. The plugin at the link below will allow for PHP code to be used in your pages.
Another option with reported success:
The following video walks you through the steps needed to make sure your button code is setup properly. This is not a professional video, just something we made on-the-fly for a customer.