chmod 666 is invalid, it should be octal: 0666

but i'd rather not chmod at all, if webserver can write it, so can it read it.

really, it should be configurable (perhaps take some cacti var?)
--- cacti-plugin-boost-4.3/setup.php~	2010-12-14 09:15:05.048058428 +0200
+++ cacti-plugin-boost-4.3/setup.php	2010-12-14 23:38:26.442892330 +0200
@@ -929,7 +929,6 @@
 						if ($fileptr = fopen($cache_file, "w")) {
 							fwrite($fileptr, $data["output"], strlen($data["output"]));
 							fclose($fileptr);
-							chmod($cache_file, 666);
 						}
 					}
 				}else{