MyBB Community Forums

So I followed Matt's guide on how to set the cookies etc in the sticky on this forum and I am still having trouble logging in. I click login on the admin panel and I'm taken to the dashboard, once I navigate away from that page, it logs me out.

It doesn't even log me in as normal user, it says I'm successfully logged in, but when it refreshes, I'm not.

It's on a sub-domain and I've tried the following (changed in phpMyAdmin and /inc/settings.php:

subdomain.mydomain.net
.mydomain.net

/
/folder/

None of the above seem to be working. The forum isn't live yet, so I'll have to send you a PM with the URL.

It's been 3 days now and I still can't find a way to fix this.

Re-Install MyBB & in the installation use a different MySQL database. This problem is caused lots due to the database being used for another forum already, Just re-install + use a different database.

I'm not using the database with anything else though.

I installed MYBB with MySQL Improved.
When I login to Admin and try any of the links on the left side, i.e. for Preferences or Add New Forum; I am asked for login again and this time when I use my admin login it does not log me in !!!!! I can't do anything in the back end.

Any help is appreciated.