The latest official release is not compatible with Firefox 3. This is because Firefox 3 has added the "charset" directive in the Content-Type HTTP header. As a result Porcupine cannot detect an XML-RPC request initiated by Firefox 3. Here is a quick fix.
The new web site is far more friendly for search engines and more consistent than the old one in terms of putting things where it should be and not having pieces of relevant information scattered in different sections. I hope you like the new design.