> Uwe Brauer <oub@mat.ucm.es> writes:

> Right, and `message-yank-prefix' (which gets used as the value of
> `comment-start') has a space, meaning those lines aren't recognized as
> comments.

> Maybe try setting `message-yank-empty-prefix' to "> "? For your own
> citations, anyway, that ought to ensure the space is there. I don't know
> about other people's citations, though...

Thanks but I found the problem. I am using a quite old package from Noah
Friedman called comment.el which uses a function comment-out-region. For
this function to work he has set a variable comment-mode-alist via
defvar, and it the latest emacs version this variable is not set. I will
ask him (I think he still active) and in emacs-devel.

Uwe