SMF and MediaWiki error-- cannot log in

[Shyam09]

I downloaded the Auth_SMF.php from github.com/SimpleMachines/smf-mw-auth [nofollow]
I installed Media Wiki (the latest) and moved LocalSettings.php to the root of the mediawiki folder. I uploaded Auth_SMF.php to w(mediawiki)/extensions/
I edited the LocalSettings.php with Microsoft Web Matrix and added whatever Step 5 stated to add.

when I go to the index page of my wiki, I get the following error:
Fatal error: Class 'Auth_SMF' not found in /home/site/public_html/w/LocalSettings.php on line 186

Line 184-186:
# Load up the extension
require_once "$IP/extensions/Auth_SMF.php";
$wgAuth = new Auth_SMF();

Thanks

UPDATE: figured out that error, but now I cannot log in to the Wiki with neither my SMF account nor the admin account created during installation of wiki

[Arantor]

"the latest" is not a version. What versions are you using?

[Shyam09]

1.21.3 with SMF 2.0.6

I figured out that mistake, a simple (yet stupid) download mistake..

I also have come across this error:
I cannot log in to the Wiki Page be it through the login I setup during installation of MediaWiki nor the UN/PW of my SMF account.

Also, I set my MediaWiki to Private during installation. Could that be it?