If I add an image with a caption using the tinyMCE editor it generates the code below which is displayed properly in the WP editor and if I preview the post from outside the forum.
[caption id="attachment_683" align="alignnone" width="300"]<a href="/wp-content/uploads/2014/08/IMG_0089.jpg"><img class="size-medium wp-image-683" src="/wp-content/uploads/2014/08/IMG_0089-300x225.jpg" alt="An image description" width="300" height="225" /></a>My image caption[/caption]
However, once the post is added to the forum, I get the image but the caption codes are ignored.
[caption id="attachment_683" align="alignnone" width="300"]
<my image here>
My image caption[/caption]
I have tried switching Themes to Twenty Fiifteen and Twenty Thirteen but the problem persists.
My site here
WP Version 4.1.1
BB Press Version 2.5.4