ditto,
my view for what its worth (not directed at anyone BTW)
companies should either
1. use the forum to promote your business and be very selective over other engagement. Its a marketing chanel but one that needs to be used carefully due to the open nature of a forum.
2. use it as a personal forum for banter, discussion.
don't mix the two. If you use it for 1 you have to accept people may say bad things or critise now and then, its an open forum that stuff happens, its not nice just ignore it and focus on the delivery of good stuff. Its kind of like dancing with the devil
Forums are a form of social media, a very powerful marketing tool like twitter and facebook. Use them wrongly and they bite!