i could not find a solution for this so i just had a look for this:
i am using the 1st Page News Addon, by including it to various Pages as right handed window, loaded from the header (my page internal, not the forums one) to the main context. so when it comes to display the forum, the forums header loads mine, and this loads first page addon, leading into a ugly error.
In 1st page addon there is a simple Flag to set if the includes are used:
some lines below used for:
so this isnt realy good, causing my page to blow up. if some one has a similar problem, simply replace the if/include part with
(by the way this works maybe only for me, because my firstpagenews is displayd after the forum in the footer)
so this should be fixed in general in minibb / first page addon, using your defines to excude double includes. my solution works for me, if some one realy goes in this, a change of include to include_once may helps.
edit: forgot to mention, all those code above is in the addon_1stpagenews2.php