Failed to Login with Created Account in Community Auth

Hello,
I'm currently develop an application using Community Auth, and after initially having no problem setting it all up, I now have weird issue where I can't login using my created user.

Previously, I created 2 accounts (both with admin privilege) using the original 'create_user' method from Examples controller (only slightly modified in terms of group id). The user are created successfully, and I can login using those 2 accounts with no problem.

Now, whenever I create new account (still using the same method), whether it's a regular member or an admin, I can't seem to login using those newly created account. 

Here's what the log said:

Code:

DEBUG - 2016-03-01 15:54:25 --> UTF-8 Support Enabled
DEBUG - 2016-03-01 15:54:25 --> Global POST, GET and COOKIE data sanitized
DEBUG - 2016-03-01 15:54:25 --> Config file loaded: C:\xampp\htdocs\planid\application\third_party/community_auth/config/db_tables.php
DEBUG - 2016-03-01 15:54:25 --> Config file loaded: C:\xampp\htdocs\planid\application\third_party/community_auth/config/authentication.php
DEBUG - 2016-03-01 15:54:27 --> Encryption: Auto-configured driver 'openssl'.
DEBUG - 2016-03-01 15:54:27 -->
string     = user1
password   = UserPass1
form_token = fc597a77
token_jar  = ["fc597a77"]
DEBUG - 2016-03-01 15:54:27 --> Config file loaded: C:\xampp\htdocs\planid\application\third_party/community_auth/config/form_validation/login.php
DEBUG - 2016-03-01 15:54:27 -->
NO MATCH FOR USERNAME OR EMAIL DURING LOGIN ATTEMPT
DEBUG - 2016-03-01 15:54:27 --> Total execution time: 1.4039

After some reading (http://stackoverflow.com/questions/31271...odeigniter), I initially thought it's related to me changing encryption key. Truthfully, I don't remember whether I created the first 2 accounts before of after filling out the encryption_key variable in config/config.php. So I tried changing the key, both leaving it empty or using new key created using the Key_creator.php, sadly to no avail.

My PHP version is 5.4.7, and I've already tried to print out the posted password using crypt( $password, $hash ), with $password is the posted password and I retrieve $hash from my database, and both have the same value.

Any suggestion will be helpful. Let me know if you need any more information.