concrete5 programmatically created user can't log in - php

Question

I've got a C5 site wherein I need to programmatically create user accounts. What I've done is use the register method of the UserInfo class, which seems to work. Problem is none of the users created this way are able to log in, the C5 login page just returns "Invalid email address or password."
I've checked and they are showing up in the users table. I've tried copying the password hash for a user who can log in, but the programmatically created user still can't log in. I've also asked another dev I know and after looking at the code says it's practically identical to how he's done this in the past. At this point I'm a bit stumped on how to move forward with troubleshooting this.
If it makes a difference the site is set to use email addresses instead of usernames for login.
//name = guy incognito \ both passed in
//email = 1234#5678.com \ via POST
function getRandomString($length) {
$seed = chr(mt_rand(97 ,122)).substr(md5(time( )), 1);
$rand = "";
for($y = 0; $y <= $length; $y++) {
$rand .= substr($seed, rand(0, strlen($seed)), 1);
}
return $rand;
}
$pswd = getRandomString(8);
$userData['uName'] = md5($name . rand(1, 1000) . date('Y-m-d H:i:s'));
$userData['uEmail'] = $email;
$userData['uPassword'] = $pswd;
$userData['uPasswordConfirm'] = $pswd;
$ui = UserInfo::register($userData);
Here's a screen capture of the entry created in the user table:
http://i.stack.imgur.com/N1ebw.png (unfortunately I lack the reputation to post images directly)
Edit - 19/09/2014
Having worked on this a little further I've traced the problem down into the checkPassword function of the 3rd party phpass library C5 is using. The hash it's generating when it checks during login is different than the hash generated at the time of account creation.
account creation hash = $2a$12$6UZ//BGdH6sO2AhfykvyHOLfzR2ADOuQVnzcFu6P9FckbJ56Y40WW
login attempt hash = $2a$12$6UZ//BGdH6sO2AhfykvyHOoxM727vGVnxo.3VsFYwDjKUM13SJqtO

Answer 1

After looking at concrete/core/dashboard/users/add.php I noticed they were registering users in a slightly different manner. Here they aren't passing a password confirmation, are specifying a default language, and most noticeably not calling UserInfo::Register but instead UserInfo::Add.
After updating my code to reflect how it was being done there things work. For the record:
$uName = md5($_POST['repName'] . rand(1, 1000) . date('Y-m-d H:i:s'));
$data = array('uName' => $uName, 'uPassword' => $authCode, 'uEmail' => $_POST['repEmail'], 'uDefaultLanguage' => 'En');
$ui = UserInfo::add($data);