msphpsql crash on fetching

test.php

<?php

$mssql_resource = sqlsrv_connect(MSSQL_HOST, array("Database" => MSSQL_DATABASE, "UID" => MSSQL_USER, "PWD" => MSSQL_PASSWORD, "CharacterSet" => "UTF-8"));
if(is_resource($mssql_resource)) {


	// Query WITHOUT parameters and DEFINED fetchType: Works fine
	$stmt = sqlsrv_prepare($mssql_resource, "SELECT TOP 5 * FROM [table]");
	if($stmt !== false) {
		if(sqlsrv_execute($stmt)) {
			 while(is_array($row = sqlsrv_fetch_array($stmt, SQLSRV_FETCH_ASSOC))) {
				 var_dump($row);
			 }
		} else print("exec failed");
	} else print("stmt failed");
	
	// Query WITHOUT parameters and UNDEFINED fetchType: Works fine
	$stmt = sqlsrv_prepare($mssql_resource, "SELECT TOP 5 * FROM [table]");
	if($stmt !== false) {
		if(sqlsrv_execute($stmt)) {
			 while(is_array($row = sqlsrv_fetch_array($stmt))) {
				 var_dump($row);
			 }
		} else print("exec failed");
	} else print("stmt failed");
	
	// Query WITH parameters and DEFINED fetchType: Works fine
	$colval = 10;
	$stmt = sqlsrv_prepare($mssql_resource, "SELECT TOP 5 * FROM [table] WHERE [col] = ?", array(&$colval));
	if($stmt !== false) {
		if(sqlsrv_execute($stmt)) {
			 while(is_array($row = sqlsrv_fetch_array($stmt, SQLSRV_FETCH_ASSOC))) {
				 var_dump($row);
			 }
		} else print("exec failed");
	} else print("stmt failed");
	
	// Query WITH parameters and UNDEFINED fetchType: Crashes PHP with exit code 255
	$colval = 10;
	$stmt = sqlsrv_prepare($mssql_resource, "SELECT TOP 5 * FROM [table] WHERE [col] = ?", array(&$colval));
	if($stmt !== false) {
		if(sqlsrv_execute($stmt)) {
			 while(is_array($row = sqlsrv_fetch_array($stmt))) {
				 var_dump($row);
			 }
		} else print("exec failed");
	} else print("stmt failed");
	
	
	sqlsrv_close($mssql_resource);
} else die("connection failed");