Hi Giz..
I'd say you may have a cookie issue using your subdomain (bbs.rsownersclub.co.uk)
Now when you setup your installation of photopost you would have the setting : 'photopost cookie domain' make sure it's the same as your vbulletin cookie domain, i.e "rsownersclub.co.uk" (not 3 dots...but 2)
Check your vbulletin cookie settings then match them in the photopost cookie settings, you may have to go via phpmyadmin to alter those photopost settings - also check that your vbulletin usergroup id for your account (default = 6 - administrator) is setup the same in the 'usergroups' field in the photopost table.
-T