I am setting up a site for a friend and he likes the Afterburner look.
We have p8pBB as the bridge for Joomla/CB <-> phpBB3 and with p8pBB the forums is in a wrapper in Joomla. Therefore the sidebar that shows up in the forum is not needed since the Joomla sidebar is still there.
So I want to strip down the phpBB style from that. I suspect that RokBB3 palys apart here too.
Gantry, configure the specific menu item (the page wrapping your forum) under "Menu Items". When you click this, notice that all the settings (which are default) can be overridden. Under "Advanced" Tab, make sure that you only have one item in the mainbody by setting "Force Position" to "ON" and "Position Count" to "1".