.htaccess problem
 

I have 3 sites 1 wordpress, 1 vbulletin, 1 website everything was working fine for months nothing was changed suddenly the blog started throwing a 404, the vbulletin was fine the website was fine. Server tech support traced to .htaccess which has vbseo code in it. Whenever I activate the .htaccess with the vbseo the blog throws a 404 and the sitemap gets generated and sent to search engines, when I put in the simplified .htaccess the blog and everything works fine however no search engine submittal. "Nothing was manually changes to cause this I am totaly lost and server side is not familiar with vbseo! HELP Please Cut and paste of 2 .htaccess files below. Thanks to anyone for ideas on how to solve.
vbseo version"
AddType x-mapp-php5 .php
# 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
RewriteCond %{HTTP_COOKIE} _bb_welcome
RewriteRule .* - [F]
# 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 /

RewriteCond %{HTTP_HOST} !^www\.mysiteforums\.com
RewriteRule (.*) http://www.mysiteforums/forums/$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]

Short version:
RewriteEngine on
RewriteCond %{HTTP_HOST} ^mysiteforums.com [NC]
RewriteRule ^(.*)$ http://www.mysiteforums.com [L,R=301]
RewriteRule testpage\.html http://www.google.com [R]
AddType x-mapp-php5 .php
Options +FollowSymLinks
Thanks,
bb

I think you should ask this at vBseo in the forums. They have great knowledge of this stuff.

I know I have vBSEO and sometimes I have random problems like this once in a blue moon.