thanks for your quick answer !
I installed a second version of the 1.8.6 in a new directory, without changing anything in the files.
For a test I crawled the index page of PHP Dig, which is on ISO-8859-1.
The config file is also on : define('PHPDIG_ENCODING','iso-8859-1');
But still i get those annoying \3 and also \1 in the title of the found page, see attached for details.
Don't see what else to do to fix it ; waiting for some help...
Thanks.