How to stop Non-WWW Wordpress MU getting redirected to signup/register page?

So we have Worpress MU install and removed the WWW in the URL, as mentioned here

Why is it that when we go to - it loads correctly
but when we use
it redirects to

We are aware that the /register/ page is set by Buddypress as we are using it as well.

Since we originally had a www on the site, our browsers now change the url to if we enter in

How do we stop the redirection from happening even if we enter in the URL with WWW?

Please advise.