Sorry, I forgot to check this forum for a while.
I will prepare the patch for you and put it somewhere for download over the next week or two. We've been using and expanding on it for quite a while. I added some ajax style "web 2.0" stuff to expand parent tasks too. (it shows child tasks easily)
However this patch is still for 1.8 as we haven't upgraded to later versions of mantis yet. (however, I don't see why people would have too much of a problem adapting the code to later versions as the patch isn't that complex)