By default, only the Portal uses the Layout Framework. You can enable the framework for various sections of your website (as well as enable articles mode). If you enable the framework for a section, you must define a custom layout for that section, or it's fallback.
So if you enable the framework for "Forum", you can start defining custom layouts for each forum individually using "forum-#", where "#" is the node-id of that forum. If it can't find a custom layout defined for a forum, it will look for the fallback layout called "forum".
In other words, "forum-3" would the layout for the forum node of 3. While "forum" will be the layout for ALL forums that don't have custom layouts. You can chose not to have a layout called "forum" at all, so that your forums don't have layouts unless explicitly defined.
Show Navigation Tab?
Yes. I did not disable it but rather 'unchecked' the [Forum (forum-#=>forum] and left the [Index(index > portal] checked. That fixed he issue and Thanks Jake.