Please try using this CVS snapshot:

  http://snaps.php.net/php4-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php4-win32-latest.zip

I have tried the latest PHP CVS 4.4.0-dev(200212120030).
The problem still exist. All "big 5" characters from HTML form POST/GET are always converted to HTML codes. No function can be used to convert HTML codes back to "big 5" characters.

Thanks.

2)htmlentities has an extra optional argument for characterset

Can you double check what that the brower is sending to the server (karpski), and see if theres any difference between you r Apache1.3 & Apache2.0 setup

I use the same client (Windows2000 + IE6), the same server OS (Redhat7.2) and the same php version (4.2.3 and 4.4.0-dev). The only difference is Apache version, Apache1.3.27 and Apache2.0.40. 

For testing, I use the "big 5" character "?O?}"
From Apache1.3.27:
$_REQUEST = "?O?}"

From Apache2.0.40:
$_REQUEST = "保良"


The setup of both Apache servers are equal.
Apache1.3.27:
'./configure' '--with-mysql' '--with-apxs=/usr/local/apache/bin/apxs' '--with-imap' '--with-kerberos' '--with-imap-ssl' '--with-gettext' '--with-xml' '--with-ldap' '--enable-ftp'

Apache2.0.40:
'./configure' '--with-mysql' '--with-apxs2=/usr/local/apache2/bin/apxs' '--with-imap' '--with-kerberos' '--with-imap-ssl' '--with-gettext' '--with-xml' '--with-ldap' '--enable-ftp' 


Thanks for help.

It appears that apache 2 is correctly encoding the input, I would suggest a having a look at the multibyte extension, to see if there is a way of 
a) configuring php to automatically decode these for you
b) a routine to manually decode them.

I suspect some external input filter module automatically converts multibyte characters to htmlentities before they come into PHP's input handler.

If so, this is not the PHP developer issue.

What modules are enabled in Apache2? you can get the list of   built-in modules by the following option:

$ httpd -l

I have checked the built-in modules of both Apache 1.3 and Apache 2. They have the same modules:
Compiled in modules:
  core.c
  http_core.c
  mod_access.c
  mod_actions.c
  mod_alias.c
  mod_asis.c
  mod_auth.c
  mod_autoindex.c
  mod_cgi.c
  mod_dir.c
  mod_env.c
  mod_imap.c
  mod_include.c
  mod_log_config.c
  mod_mime.c
  mod_negotiation.c
  mod_setenvif.c
  mod_so.c
  mod_status.c
  mod_userdir.c
  prefork.c

Thanks.

Sorry, but your problem does not imply a bug in PHP itself.  For a
list of more appropriate places to ask for help using PHP, please
visit http://www.php.net/support.php as this bug system is not the
appropriate forum for asking support questions. 

Thank you for your interest in PHP.

External applications often will convert non-ascii characters to their htmlenties equivalents when pasting data into a web browser form(s). This has nothing to do with PHP itself.