mytheme_preprocess_field is not called on add/edit node I have added the following function in my theme's template.php to test whether it actually gets called when adding or editing a node, but for some reason it is not!

function mytheme_preprocess_field(&amp;$variables, $hook) {
    die('FINALLY!');
}

I have done everything I could think off, refresh cache (all of them), restart apache, restart server, no matter what I do, it is not called. As soon as I go to the frontpage, it is called. 

Can someone give me some pointers where I might look next? Thanks!
I believe the theme functions are called on render (as in view) and not the add/edit pages.  If you want to affect the markup of the fields on the add/edit forms you would use a hook_form_alter or hook_form_FORM_ID_alter() and change the render array there.