Why is 'www.' disappearing?
 

How come my url sets to 'http://mysite.com/forums' and exludes the 'www'? If you add that, it will just change to the aforementioned. The Forum URL in vBulletin options has the 'www'.

Not many user(s) type www. I just type my domain without the "www" and it still loads. Those who don't know, types the www.site.com

That doesn't explain why it's doing it though, since there are forums where the 'www' remains regardless.

You'll have to ask your host provider on what they dont' allow "www."

I nor anyone (maybe they can) can tell you why it's happening to you. You'll just have to ask them your-self.

most likely answer is a rewrite in httpd.conf

It's a good thing, avoids cookie clashes, I use it for all my sites.

Could this be an error in your vBulletin options?
Try editing..

http://www.Yoursite/vBulletin/adminc...ons.php?null=0
Then go to "Site Name / URL / Contact Details"
Then edit "Forum URL".

Let me know how you get off ;)

Funny, I use a rewrite rule to force the www. Some browsers will not retain cookies if they don't come in under the www (I don't recall which, I just no I got tons of complaints).

Add this to your htaccess file in the public html folder.

Options +FollowSymlinks
RewriteEngine on
rewritecond %{http_host} ^your-main-domain\.com [nc]
rewriterule ^(.*)$ http://www.your-main-domain.com/$1 [r=301,nc]

No more issues! But this will force the www on you!

Thanks, Quarterbore. That's fixed it. =)