Whats happened to the PPC forum, it looks very different and my bookmarked page leads to a 404... worst of all it doesn't recognise my login

You need to ask for a password renewal. All your details have been transferred to the new webby but the passwords havn't.
Here's the new one:
http://www.ppcmag.co.uk/forum/

And here's the 'intermediate' one that cost PPC a fortune but didn't work:
http://www.ppcmag.co.uk/index.php?option=com_kunena&Itemid=7

Your a star, cheers!