Replication Code:
<?php
# Connect to DB
$db = mysqli_connect('localhost','root','','');
$res = mysqli_query($db, 'CREATE TEMPORARY TABLE tst1 (c1 VARCHAR(8), c2 VARCHAR(8))');
$res = mysqli_query($db, 'INSERT INTO tst1 (c1, c2) VALUES ("aa","bb"), ("cc","dd")');
$res = mysqli_query($db, 'SELECT * FROM tst1');
$data = mysqli_fetch_assoc($res);
var_dump($data);
?>
Never reaches VAR_DUMP(); Errors on MYSQLI_FETCH_ASSOC(); PHP has encountered an Access Violation at 004B2BEB

Please try using this CVS snapshot:

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

  http://windows.php.net/snapshots/

For me, the latest Windows VC6 thread safe snapshot, dated 2009-Feb-05 12:00:00, did not work.

My machine:
Windows XP Pro SP3
IIS 5.1, with PHP ISAPI module

(If this is not helpful, please accept my apologies and delete.)

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".

Same problem, seems to be column related. Test cases below
Cheers,
Mark

<?php
// MySQL libmysql.dll version from MySQL 5.1.30 ( Version 5.1.30 )
// PHP version 5.2.8
// When using the libmysql.dll version that came with PHP 5.2.8 all works fine ( version is 5.0.51a )
// Problem seems to be when multiple columns are mentioned.
// OS Windows Vista on IIS 7
// Browser IE7 and FireFox ( Only Firefox shows the error, IE7 gives a HTTP 500 error )
// PHP version 5.2.8 ( ISAPI )
// MySQL 5.1.30
// My workaround is to is use the library that came with PHP
//

// Fails with PHP has encountered an Access Violation at 01582BEB
$mysqli = new mysqli("localhost", "my_user", "my_password", "my_db");
$result = $mysqli->query("SELECT id, admin_name FROM admin_users LIMIT 1");
$row = $result->fetch_object();
$result->close();
echo $row->id;

// Works with 2nd column name removed
$mysqli = new mysqli("localhost", "my_user", "my_password", "my_db");
$result = $mysqli->query("SELECT id FROM admin_users LIMIT 1");
$row = $result->fetch_object();
$result->close();
echo $row->id;

// Works with single column
$mysqli = new mysqli("localhost", "my_user", "my_password", "my_db");
$result = $mysqli->query("SELECT admin_name FROM admin_users LIMIT 1");
$row = $result->fetch_object();
$result->close();
echo $row->admin_name;

// mysql also fails with PHP has encountered an Access Violation at 021EAC5A
$link = mysql_connect('localhost', 'my_user', 'my_password');
$result = mysql_query("SELECT id, admin_name FROM admin_users LIMIT 1");
$row = mysql_fetch_row($result);
mysql_close($link);
echo $row[0];
echo $row[1];

// Also fails with one column selected :-(
$link = mysql_connect('localhost', 'my_user', 'my_password');
$result = mysql_query("SELECT id FROM admin_users LIMIT 1");
$row = mysql_fetch_row($result);
mysql_close($link);
echo $row[0];
?>