Why won't member.php work outside the forum directory?

[Opserty]

Your best bet would be to duplicate the functions you want in a custom file. Like Marco said these files aren't coded to be in other directories so you will encounter many problems to which there is no point trying to fix as it will be a heck of a lot of work.

Set up the other member.php page to redirect to your forum member.php page. Or else you can try creating your own page: How to create your own vBulletin-powered page! (uses vB templates)