Xoops bug: I can't add a new user

Help me! I can't add a new user to Xoops.
I recently installed the latest version, Xoops 2.0.10 JP.

When I try to add a new user, Xoops says "必要なデータを全て入力してください".
What? I filled all the required fields!
This is a bug?

To understand the problem, I repeated the following grep commands.

$ cd ~/public_html/xoops-2.0.10-JP/html
$ grep -rn "必要なデータを全て入力してください" .
./language/japanese/search.php:4:define('_SR_PLZENTER',
'必要なデータを全て入力してください。
./modules/system/language/japanese/admin/users.php:9:
define("_AM_YMCACF","必要なデータを全て

$ grep -rn "_AM_YMCACF" .
./modules/system/admin/users/main.php:234:        
$adduser_errormsg = _AM_YMCACF;
./modules/system/language/english/admin/users.php:10:
define("_AM_YMCACF","You must complete
./modules/system/language/japanese/admin/users.php:9:
define("_AM_YMCACF","必要なデータを全て

And then, I opened the modules/system/admin/users/main.php with vi.

I gave an eye to a piece of the code at line 229:

$myts =& MyTextSanitizer::getInstance();
$username = !empty($_POST['username']) ? 
$myts->stripSlashesGPC(trim($_POST['username'])) : '';
$email = !empty($_POST['email']) ? 
$myts->stripSlashesGPC(trim($_POST['email'])) : '';
$password = !empty($_POST['password']) ? 
$myts->stripSlashesGPC(trim($_POST['password'])) : '';
if ($username == '' || $email == '' || $password == '') {
    $adduser_errormsg = _AM_YMCACF;
} else {

Again, I checked posted data with Live HTTP headers(a useful Firefox plugin).

This is the posted data:

XOOPS_TOKEN_users_addUser_1=e7453c883650b5a2e80fb1e89ea42ec8&
username=test&name=test&email=test%40email&url=&timezone_offset=0&
user_icq=&user_aim=&user_yim=&user_msnm=&user_from=&user_occ=&
user_intrest=&user_sig=&umode=nest&uorder=0&notify_method=1&
notify_mode=0&bio=&rank=0&pass=test&pass2=test&user_mailok=0&
groups%5B%5D=2&fct=users&op=addUser&submit=%C1%F7%BF%AE

Where is the field "password"?
There are "pass" and "pass2" field, but not "password".

This is a bug!

Some Xoops user has already reported the bug found at the Xoops Bug Forum.