Subdomain issues.

There is something with the mod rewrite that is causing my subdomain to not function properly.

What is happening is the subdomain is acting as a folder behind the main domain, like this,

Let say I have this setup for my subdomain.
sub.xxxx.com

And this is where it is actually working,
www.xxxx.com/sub

I have been on the phone with my host to fix the problem, but they don't know what's going on, other then the problem is in the modrewrite which is this .htaccess file.

Comment the following line (add '#' at the beginning)
# to disable mod_rewrite functions.
# Please note: you still need to disable the hack in
# the vBSEO control panel to stop url rewrites.
RewriteEngine On
# Some servers require the Rewritebase directive to be
# enabled (remove '#' at the beginning to activate)
# Please note: when enabled, you must include the path
# to your root vB folder (i.e. RewriteBase /forums)
#RewriteBase /
RewriteRule ^((urllist|sitemap).*\.(xml|txt)(\.gz)?)$ vbseo_sitemap/vbseo_getsitemap.php?sitemap=$1 [L]
RewriteCond %{REQUEST_FILENAME} -f
RewriteCond %{REQUEST_FILENAME} (admincp|modcp|clientscript|cpstyles|images)/
RewriteRule ^(.*)$ $1 [L]
RewriteCond %{QUERY_STRING} !vbseourl=
RewriteCond %{REQUEST_FILENAME} !chat
RewriteRule ^(.*\.php)$ vbseo.php?vbseourl=$1&%{QUERY_STRING} [L]
RewriteRule ^(archive/.*)$ vbseo.php?vbseourl=$1&%{QUERY_STRING} [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.+)$ vbseo.php?vbseourl=$1&%{QUERY_STRING} [L]

That took care of the internal error on the subdomain. I still have the page showing in the two places though.

I'm on a vps. Would it matter that the server name is, for example,
host.xyz.com

and my domain is
xyz.com

Would them being some what the same having anything to do with this?

Anyone else have a vps here with subdomain setup?

Yes that fixed it.

Thank you!