[ShawneyJ]

to me it looks all wrong while using vbseo.
try this mate!
completely remove all your .htaccess and add (copy and paste) all this:

# 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 /

#RewriteCond %{HTTP_HOST} !^www\.webmasterforumuk\.net
#RewriteRule (.*) http://www.webmasterforumuk.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]

next make sure in "Site Name / URL / Contact Details" look like in attachment below all with www.
and last...i use this small addon which works a treat when i was using vbulletin. i would give it a go mate, its awesome. https://vborg.vbsupport.ru/showthrea...=222898&page=4

I have turned "Add No-Cache HTTP Headers" option to "yes". Is it wise to turn this option yes?

IMO no. but if you find your forum slower loading posts turn it back off.

its the only thing i can come up with to fix this issue.