MyBB Community Forums

I'm running 1.6.2 - might be why?

I'll have a look at upgrading.

If you need help regarding upgrading, see the Wiki: http://wiki.mybb.com/index.php/Upgrading

Yes, the double posting bug was fixed in 1.6.3.

Bleh, isn't the easiest thing to do in the world, my tiny mind slightly expected yet more so wanted, it to be as simple as clicking 'upgrade to latest version'

You just need to download the changed files package from the announcement, upload the contents of it so the files overwrite your current files, and then run the upgrade script. If you're running a forum you'll need to learn how to perform simple operations such as this at some point.