Leading * prefix in c mode comments doesn't work well

[xubio1]

I am trying to get c-mode block comments to automatically insert
leading '* ' in each line in a block comment.  I tried setting c-block-
comment-prefix to '* ', and this works to auto-insert the prefix on
the second line of a comment block but only if the the newline is auto-
inserted.  If I use a manual return (which for me is bound to newline-
and-indent), the prefix is not inserted.  And all subsequent lines of
the block comment do not receive the prefix, whether from auto-fill or
by manual newline-and-indent.  c-comment-prefix-regexp is set to:
((pike-mode . "//+!?\\|\\**")
 (other . "//+\\|\\**"))

I'm using GNU Emacs 21.3.1 with C Mode 5.28.

Surely I must be doing something wrong, because Emacs and C-mode are
too perfect to not be able to do this.