vBSEO Small Problem! Please Help

Hello,

A friend of mine have some problems with vBSEO and he dont know English so he asked me to support him.

His problem:
He have Hosting at globat.com lets say www.domain.com
and his vBulletin directory is at www.domain.com/vb

now he bought a new domain www.newdomain.com and he pointed his domain at www.domain.com/vb

Forum was working wonderful, and he have installed vBSEO but It seems that he have some Rewrite problems.

when he turns at .htaccess
Rewrite Engine On
Rewrite Base /vb/

his forum works only from www.domain.com/vb

If he access his forum from www.newforum.com and opens a thread than it becomes www.newforum.com/vb .

I know that problem is somewhere with rewritecond or rewriterule but I dont have experience...

His .htaccess looks like :

# 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 /vb/

#RewriteCond %{HTTP_HOST} !^www\.newdomain\.com
#RewriteRule (.*) http://www.newdomain.com/$1 [L,R=301]

RewriteRule ^((urllist|sitemap_).*\.(xml|txt)(\.gz)?)$ vbseo_sitemap/vbseo_getsitemap.php?sitemap=$1 [L]

RewriteCond %{REQUEST_URI} !(admincp/|modcp/|cron|vbseo_sitemap)
RewriteRule ^((archive/)?(.*\.php(/.*)?))$ vbseo.php [L,QSA]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !^(admincp|modcp|clientscript|cpstyles|images)/
RewriteRule ^(.+)$ vbseo.php [L,QSA]

Code (markup):

Hope someone will help me,
Sorry for my bad english,
Thank you very much,
Regards,