MK boys. I'll explain it since I had all of those problems.
Install it as is explained in the tutorial.
Find your conf.php and manually enter the details with a text editor. (notepad etc)
it WILL not update via admin panel in IPBoard.
find your api, (for whcms) should be <install folder>/includes/api.php
go to it in your BROWSER. <site>/<install folder>/includes/api.php
MAKE SURE ITS THERE. if you get invalid IP, add your IP to the list in WHMCS (general setup, security, towards the bottom HIT SAVE OR IT WON"T SAVE!!!!)
reload api.php once it says authentication failed, you are set to go.