It appears that using $this->here for the url option in Form->create() doesn't work when using the forum in a subdirectory.
For example, I'm using the forum as http://sites2/forumtest/forum
$this->here returns: /forumtest/forum/topics/add/general-discussion
However Form->create() will prepend /forumtest resulting in /forumtest/forumtest/forum/topics/add/general-discussion making all forms using $this->here to produce a missing controller error.
It appears that using $this->here for the url option in Form->create() doesn't work when using the forum in a subdirectory.
For example, I'm using the forum as http://sites2/forumtest/forum $this->here returns: /forumtest/forum/topics/add/general-discussion
However Form->create() will prepend /forumtest resulting in /forumtest/forumtest/forum/topics/add/general-discussion making all forms using $this->here to produce a missing controller error.