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!