You can keep /portal in Home URL if that's how you want it, I was wondering the values of your settings is all. The PhotoPlog URL isn't a setting though, it's just the link to PhotoPlog on your site.
The 'Reload this Page' breadcrumb link is coming out like that because $scriptpath is returning
/portal/photoplog/index.php and then PhotoPlog sees it's a relative link and prepends
http://www.domain.com/portal/forums to form the link you see.
The duplicate directory, while thought of as the part to take off the end of the Forum URL, really comes off the beginning of relative links in the HTML source of a page.
In the photoplog_output_error and photoplog_output_page functions, right after all the global bits, add the following:
Code:
Content visible to registered users only.