protected function tryToLoadFromCache( $cacheFile, $lastChange )
	{
		if( !file_exists( $cacheFile ) )
			return FALSE;

		$lastCache	= @filemtime( $cacheFile );
		if( $lastCache && $lastChange <= $lastCache )
		{
			$content	= file_get_contents( $cacheFile );
			$array		= @unserialize( $content );
			if( is_array( $array ) )
			{
				$this->pairs	= $array;
				return TRUE;
			}
		}
		return FALSE;
	}