I figured it out too. I was gonna post, but you beat me to it

I was also installing other PHP bbs scripts from other sites and I had the same problem with zorum and XMB.
I saw a post for the resolution on the XMB forum and relized this was te problem for all of them. In the PHP file the comments for the gobals says that they made it no by default because developers should try not to use gobals. but I think it is stupid for zend to impose how the developers make scripts in PHP by making that a default.