I found that if I put require_once at the end of the php file, the fatal error 
won't appear any more... just inspired by another bug report.

Thank you for this bug report. To properly diagnose the problem, we
need a short but complete example script to be able to reproduce
this bug ourselves. 

A proper reproducing script starts with <?php and ends with ?>,
is max. 10-20 lines long and does not require any external 
resources such as databases, etc. If the script requires a 
database to demonstrate the issue, please make sure it creates 
all necessary tables, stored procedures etc.

Please avoid embedding huge scripts into the report.

ok, i have just know that a login is needed to download the zip file.....
now i have shorten the buggy code.

//System.php
<?php
require_once 'Utilities.php';

class TJustTest {
    public function __construct() {
    		var_dump(get_declared_classes());
    }
}

interface IInterface {
    public function Supports($AInterface);
}

class TObject implements IInterface {
		public function Supports($AInterface) {
				echo 'hi';
		}
}

class TJustAnotherTest {
		public function Foo() {
				echo 'foo';
		}
}
?>

//Utilities.php
<?php

require_once 'System.php';

class TSomethingBoring {
		public function Boring() {
				echo 'really boring';
		}
}

$a=new TJustTest();

class TMustBeWrong extends TObject {
		function Tragedy() {
				echo 'this will not be seen.';
		}
}
?>



Just run System.php to see the fatal error with other classes before TObject loaded successfully 
inside System.php

You don't happen to have any opcode cachers like APC installed?

no cacher is installed.

and something important i forgot to mention:
THIS WILL ONLY HAPPEN WHEN RUNNING THE SCRIPT, everything's all right when 
debugging.

Sorry, but your problem does not imply a bug in PHP itself.  For a
list of more appropriate places to ask for help using PHP, please
visit http://www.php.net/support.php as this bug system is not the
appropriate forum for asking support questions.  Due to the volume
of reports we can not explain in detail here why your report is not
a bug.  The support channels will be able to provide an explanation
for you.

Thank you for your interest in PHP.

TObject is not yet defined at the time TMustBeWrong line is executed, since 
require is executed before TObject definition is executed. I would suggest 
cleaning up the code and getting includes (requires) in proper order.

How is this not a bug? I am experiencing the same thing and it very much looks like a bug to me.

@sky:
As stas said three years ago, the require() will execute Utilities.php as the first thing, except that file needs something System.php defined, except that hasn't happened yet because PHP is still doing the require. The execution is out of order.
The dependency is that Utilities.php needs System.php, therefore Utilities.php must require() System.php. Not the other way around.

*require_once()