Description:
------------
Calling session_set_save_handler without calling session_start later will cause IE 7 to report that the website is having network problems.  The site will work in all other browsers, including IE8.  Disabled the great "Friendly HTTP errors" which lead to the same error.

Reproduce code:
---------------
class SessionManager {

	private $life_time;
	private $db;

	public function __construct() {
		// Read the maxlifetime setting from PHP
		$this->life_time = get_cfg_var("session.gc_maxlifetime");
		ini_set('session.gc_probability','1');

		// Register this object as the session handler
		session_set_save_handler( 
			array( &$this, "open" ), 
			array( &$this, "close" ),
			array( &$this, "read" ),
			array( &$this, "write"),
			array( &$this, "destroy"),
			array( &$this, "gc" )
		);
	}
   
	public function open() {
		global $dbhost, $dbuser, $dbpass, $dbname;
		//get a seperate connection for session management
		$this->db = new sql_db($dbhost, $dbuser, $dbpass, $dbname);
	}
	
	public function close() {
		//close the connection
		$this->db->close();
	}
	
	public function read($sessionid) {
		global $dbprefix;
		$this->cleanSQL($sessionid);
		$id = $this->db->query(
		"SELECT
			data
		FROM
			{$dbprefix}sessions
		WHERE
			sessionid='{$sessionid}'
			AND expire > UNIX_TIMESTAMP()
		");
		if( $this->db->numrows() == 0 ) return '';
		else {
			$row = $this->db->fetchrow(0,MYSQLI_ASSOC);
			return $row['data'];
		}
	}

	public function write($sessionid, $data) {
		global $dbprefix;
		$this->cleanSQL($sessionid);
		$this->cleanSQL($data);
		$time = time() + $this->life_time;
		$this->db->query(
		"REPLACE
			{$dbprefix}sessions
		(sessionid,data,expire)
		VALUES
		(
			'{$sessionid}',
			'{$data}',
			'{$time}'
		)
		");
		return TRUE;
	}
	
	public function destroy( $sessionid ) {
		global $dbprefix;
		$this->cleanSQL($sessionid);
		$this->db->query(
		"DELETE FROM
			{$dbprefix}sessions
		WHERE
			sessionid='{$sessionid}'
		");
		return true;
	}
	
	public function gc() {
		global $dbprefix;
		$this->db->query(
		"DELETE FROM
			{$dbprefix}sessions
		WHERE
			expire < UNIX_TIMESTAMP()
		");
         return true;
	}
	
	private function cleanSQL(&$var) {
		$var = mysql_real_escape_string($var);
	}
}

$sessionmanager = new SessionManager();
echo 'it works';

Expected result:
----------------
Will print "it works" in all browsers.

Actual result:
--------------
Prints "it works" in all browsers except IE7 (Unknown if IE6 is affected.)