w00t! - fixed it....it ened up being a problem with the redirect....tried lots of different combinations..and tried updating core joomla files and vm files...in the end I put them all back to standard. (apart from, I'm using an updated seo friendly router.php that I downloaded from VM extensions website)
I changed it to -
RewriteEngine On
RewriteCond %{HTTP_HOST} ^iquarium.co.uk [NC]
RewriteRule ^(.*)$
www.iquarium.co.uk/$1
[L,R=301] <
rewrite for non-www to www
RewriteCond %{THE_REQUEST} ^GET\ .*/index\.(php|html)\ HTTP
RewriteRule ^(.*)index\.(php|html)$ /$1 [R=301,L] <
rewrite for the index.php (& .html) to root
This gets the all ok from
www.searchmasters.co.nz/redirect-check/
and the checkout works all the way to the end
Thanks as always Arfin, your a legend
Hopefully this can help someone else, if they want SEO friendly website with virtuemart and a rockettheme template