Please try using this CVS snapshot:

  http://snaps.php.net/php5.1-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php5.1-win32-latest.zip

If you're still able to reproduce it - please provide the backtrace (I can see the "Redhat" in the OS field, so I believe you should be able to use gdb for that).

Tried latest snapshot on Windows and experienced the same problem.  Unable to try newest snapshot on Redhat system as it is not under my control and is maintained via rpms.  Any way to retrieve backtrack on Windows system?

You don't have to install rpms, you can build the snapshot in your own home directory.

I can't reproduce it, btw.
What version of MySQL are you using?

Sorry, I'm not very experienced as a Linux administrator.  I think compiling PHP from scratch and installing/learning GDB is a bit over my head.  PHP takes down apache in Windows and with VS I'm able to view the assembly which points to a dword move operation.  "00648F4A  mov  dword ptr [edx],eax"  I'm happy to help any way I can but I just don't have the enviornment set up to get a backtrace (and I'm not adept enough with linux to set it up).

Thank you for this bug report. To properly diagnose the problem, we
need a backtrace to see what is happening behind the scenes. To
find out how to generate a backtrace, please read
http://bugs.php.net/bugs-generating-backtrace.php for *NIX and
http://bugs.php.net/bugs-generating-backtrace-win32.php for Win32

Once you have generated a backtrace, please submit it to this bug
report and change the status back to "Open". Thank you for helping
us make PHP better.

MySQL version is: 

5.0.15 on XP.
5.0.16 on Linux.

Yeah, that's what I think is causing it.
Could you try to install MySQL 4.x and see if you can reproduce the problem?
Also read this:
http://bugs.php.net/bugs-generating-backtrace-win32.php
http://bugs.php.net/bugs-generating-backtrace.php

Hope this is right... From Visual Studio:

>	php5ts.dll!_efree(void * ptr=0x00ed982c)  Line 303 + 0x1a bytes	C
 	php5ts.dll!zend_hash_del_key_or_index(_hashtable * ht=0x00eb4fe0, char * arKey=0x00ed9840, unsigned int nKeyLength=15, unsigned long h=0, int flag=0)  Line 490 + 0x6 bytes	C
 	php5ts.dll!zend_hash_reverse_apply(_hashtable * ht=0x00eb4fe0, int (void *, void * * *)* apply_func=0x10096c10, void * * * tsrm_ls=0x003225b8)  Line 738 + 0xf bytes	C
 	php5ts.dll!shutdown_executor(void * * * tsrm_ls=0x003225b8)  Line 268	C
 	php5ts.dll!zend_deactivate(void * * * tsrm_ls=0x003225b8)  Line 848	C
 	php5ts.dll!php_request_shutdown(void * dummy=0x00000000)  Line 1287	C
 	php.exe!main(int argc=2, char * * argv=0x00323f90)  Line 1231	C
 	php.exe!_mainCRTStartup()  + 0xe3 bytes	
 	kernel32.dll!7c816d4f() 	
 	[Frames below may be incorrect and/or missing, no symbols loaded for kernel32.dll]	
 	kernel32.dll!7c8399f3()

Yes, this is right, but it doesn't add any understanding.
Assigned to the PDO maintainer.

Please paste the script into the bug report.
I can't reach the URL you posted.

<?php

/* SQL

CREATE TABLE IF NOT EXISTS `section` (
  `id` int(10) unsigned NOT NULL auto_increment,
  `parentSectionID` int(10) unsigned NOT NULL,
  PRIMARY KEY  (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=8 ;

INSERT INTO `section` VALUES (1, 1);
INSERT INTO `section` VALUES (2, 1);
INSERT INTO `section` VALUES (3, 2);
INSERT INTO `section` VALUES (4, 1);
INSERT INTO `section` VALUES (5, 5);
INSERT INTO `section` VALUES (6, 6);
INSERT INTO `section` VALUES (7, 6);

*/

?>

<?php

global $db_host, $db_name, $db_username, $db_password;

$db_host = 'localhost';
$db_name = 'test';
$db_username = 'root';
$db_password = 'superw00t';

class section
{
    private $id = null;
    
    private $parentSectionID = null;
    
    private $childSections = array();
    
    private $status = array('consistentWithDb' => false, 'childSectionsLoaded' => false);
    
    function __construct($id)
    {
        $db = resourceHelper::getDbConn();
        
        // Validate $id and load section data
        if(!is_int($id))
        {
            throw new Exception('Invalid argument for section::loadFromDb(), $id must be an int.  Value sent was [' . $id . '] of type [' . gettype($id) . '].');
        }
        
        $this->id = $id;
        
        $query =    'SELECT parentSectionID FROM section WHERE id = :id';

        $stmt = $db->prepare($query);
        
        $stmt->bindValue(':id', $this->id , PDO::PARAM_INT);
        
        $stmt->execute();
        
        $stmt->bindColumn('parentSectionID',    $this->parentSectionID,    PDO::PARAM_INT);
        
        $stmt->fetch(PDO::FETCH_BOUND);

        $stmt = null;
        $db = null;
    }
    
     function __get($varName)
    {
        switch($varName)
        {
            case 'id':
                return (int)$this->id;
            case 'childSections':
                if(!$this->status['childSectionsLoaded'])
                {
                    $this->loadChildSections();
                }
                return $this->childSections;
            default:
                throw new Exception('Variable [' . $varName . '] is not a public member of section.');
                break;
        }
    }
        
    private function loadChildSections()
    {
        $sectionID = null;
        
        $db = resourceHelper::getDbConn();
        
        $query = 'SELECT id FROM section WHERE parentSectionID = :id AND parentSectionID != id';
        
        $stmt = $db->prepare($query);
        
        $stmt->bindValue(':id',    $this->id,    PDO::PARAM_INT);
        
        $stmt->execute();
        
        $stmt->bindColumn('id',    $sectionID,    PDO::PARAM_INT);
        
        while($stmt->fetch(PDO::FETCH_BOUND))
        {
            $this->childSections[] = new section($sectionID);
        }
        
        $this->status['childSectionsLoaded'] = true;
    }
}


class resourceHelper
{
    public static function getDbConn()
    {
        global $db_host, $db_name, $db_username, $db_password;
    
        // Create and Validate database connection
        try
        {
            $db = new PDO('mysql:host=' . $db_host . ';dbname=' . $db_name, $db_username, $db_password);
            $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        }
        catch(Exception $e)
        {
            throw new Exception('Unable to connect to database [' . $config['db']['name'] . '] using configuration file values.' . $e->getMessage());
        }
        
        return $db;
    }
}


$db = resourceHelper::getDbConn();
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

$sectionID = null;

$query = 'SELECT id FROM section WHERE id = parentSectionID';

$stmt = $db->prepare($query);

$stmt->execute();

$stmt->bindColumn('id',    $sectionID,    PDO::PARAM_INT);

while($stmt->fetch(PDO::FETCH_BOUND))
{
    $section = new section($sectionID);
    buildSectionRow($section);
}

$stmt = null;
$db = null;




function buildSectionRow(section $section, $indent = 0)
{

    echo $section->id . '<br />';

    $indent++;
    
    /*
    To reproduce error, comment out $test definition then 
    replace $test in foreach loop with $section->childSections
    */

    $test = $section->childSections;

    foreach($test as $childSection)
    {
        buildSectionRow($childSection, $indent);
    }
}
?>

I can reproduce this on linux.

It appears to be less of a problem if you avoid binding to variables that are members of an object.

I haven't been able to pinpoint exactly what the cause is, as it appears to change subtly as the script is modified.

I remember that once-upon-a-time, referencing $this inside a constructor would lead to problems, perhaps this is a manifestation of that issue.

Please try using this CVS snapshot:

  http://snaps.php.net/php5.2-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php5.2-win32-latest.zip

No feedback was provided for this bug for over a week, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".