Yep, I've been using WampServer 2 all this time. I gave up on PHP 5.2.10 and tried PHP 5.2.11. So far so good. I can now see the CB user management page!!! And I can login to the front end.

So... I guess the moral of the story (so far) is:
Use PHP 5.2.11, not PHP 5.2.5. Hopefully my host will allow it. But localhost is happy now.

Awesome, I've been waiting to play with CB subs for a week now:P

Thanks for your advice and time. Isn't software fun!