Hi guys, thanks to everybody for the replies. My mediawiki installation's version is 1.20.3, and I can't find the "highlightbroken" preference neither in LocalSettings.php or DefaultSettings.php .
Should I add it somewhere and set it to "1"??
It's a clean install, it has been working for some days, than I made some mistaken edit to LocalSettings.php and I had to replace it. Now the two above files was taken from the just downloaded archive...
Thanks in advance. Nick