color-browser: Undefined Custom theme

[Mike]

Hi,

I'm new to emacs and took color-browser to generate a custom color
theme. The theme has been written to ...-theme.el which I copied to
~/.emacs.d/themes/. I added the line
(add-to-list 'custom-theme-load-path "~/.emacs.d/themes/")
to my .emacs.

Giving
M-x customize-themes
the new theme shows up in the menu. But klicking it I get
Undefined Custom theme ...

What am I missing?

Mike