protected function synchronize()
	{
		if( file_exists( $this->syncFile ) )
		{
			$time	= filemtime( $this->syncFile );
			if( ( time() - $time ) < $this->refreshTime )
			{
				$this->syncTime	= $time;
				$this->syncDiff	= FS_File_Reader::load( $this->syncFile );
				return;
			}
		}
		$this->syncTime	= time();
		$this->syncDiff	= $this->syncTime - Net_AtomTime::getTimestamp();
		FS_File_Writer::save( $this->syncFile, $this->syncDiff );
		touch( $this->syncFile );
	}