Ok, so bascically what I'm currently doing is an error handler. I've created a Debugger class, and used set_error_handler() to use that class. So, to test this, I've tried a mysql_connect() with wrong infos, my Debugger caught that, and displayed it the way I wanted. I tried this [b]explicetly[/b] (there are no variables involved in this math): echo 4/0; On my windows server, my error handler catches it. On my linux server, it works. On my friend's server, it also works. But on my current webhost, it just doesn't work.. I get an error like: "[u]Warning: Division by zero in Unknown on line 0[/u]" . Notice the "Unknown on line 0" part. Weird? Yes it is... So, I tried that 4/0 thing without my Debugger class on my own machine as well, and I get what I'm supposed to get: "[u]Warning: Division by zero in /media/stuff/www/zeal/index.php on line 14[/u]" . There are no "Unknown on line 0" there.. After all those tests, I tried to compare php.ini files on every server, and they all look the same. But, on my webhost, Zend Optimiser was installed. Maybe the optimiser could cause this weird thing, so I installed Zend Optimiser (tried versions 2 and 3) on my linux machine, and my code was still working. No success again. So I'm asking for help here, I have no idea how to fix that, and google isn't being useful on that one.. [b]Note: [/b] All the servers I tried my code run are running PHP 5.1.4 (latest), on Apache. Please also note that I used the same code everywhere (in fact, I use SVN, so I just had to checkout my repository). Thanks in advance!