I’m having the same problem. I take it no one knows anything about this?
This is resolved now. My hosting provider changed the passwords in my config file which apparently contained illegal characters.
This is odd though. I ran the whole installation first time around with simple passwords that contained none of these characters and had exactly the same problem. I only introduced these new passwords in the second installation and I used the wordpress password generator.
I’ve no idea what’s happened here but its working now.
Thanks for your help.