Hello Getgamer.com,
I had a similar problem and the solution is rather simple.you had to edit the following code with the correct server root paths to the correct files.for example you currently have this
chdir('./forums');
require_once('./vBExternal.php');
you should have something like this..
chdir('/home/servername/public_html/forums');
require_once('/home/servername/public_html/forums'/vBExternal.php');
this should solve your problem
also not sure if this really matters but move that line of code underneath of the code "</head>" this is how i have it set on my page and it works great