This appears to indicate that the list of files here will get the forum's URL prefix that's stored under the vbulletin options.
So why when login.php is in this list and the correct url is stored in vB
's options do I not get the right path when I try to login from the gallery?
Yes, I know I could search out all references to this in my files and update them with the full path...but it seems the designers have already thought of this and that's why this option is there.
Am I not using it right?
You can try it by going here http://www.unlimitedengineering.com/gallery/
and attempting to log in.