@Spuds I got it now: it was just yet another bug I introduced trying to fix the attachments... ![Undecided :-\](https://www.elkarte.net/community/smileys/default/undecided.svg)
@Jorin now it really works, I have to say sorry, but the attachments are gone... ![Cry :'(](https://www.elkarte.net/community/smileys/default/cry.svg)
The problem was I wrote a function that was assuming the $_SESSION data for the attachments was there, but in fact there was no session data because $_SESSION is used only when uploading a post, no during the editing.
emanuele feels attachments is another piece of code that will benefit in 2.0 from a general overhaul and simplification, because at the moment is kind of totally messed (including the counter-intuitive $_POST['attach_del'])