my client can’t wait for CI 1.7.2
so i have to make several changes myself 
here what i do
A. remove by condition set_magic_quotes_runtime
file: codeigniter/CodeIgniter.php (line: 60)
if(!phpversion()=='5.3.0')
set_magic_quotes_runtime(0); // Kill magic quotes
B. remove all new object by reference, change ‘=&’ to ‘=’
from: $objects[$class] =& new $name();
became: $objects[$class] = new $name();
file: codeigniter/Common.php (line: 130)
file: codeigniter/Common.php (line: 136)
file: libraries/Loader.php (line: 255)
file: database/DB.php (line: 133)
$objects[$class] = new $name();
see: = new
C. since hyphen ‘-’ became special character in php 5.3, change this way:
file: config/config.php (line: 153)
from:
$config['permitted_uri_chars'] = 'a-z ~%.:_\-';
to:
$config['permitted_uri_chars'] = '~%.:_\-';
file: libraries/URI.php (line: 189)
from:
if ( ! preg_match("|^[".preg_quote($this->config->item('permitted_uri_chars'))."]+$|i", $str))
to:
if ( !
preg_match("|^[\w".preg_quote($this->config->item('permitted_uri_chars'))."]+$|i", $str))
wacth!:
! preg_match(”|^[\w
i hope this can help
