It's not really a hack
just a change of configuration. You have to go to Components > !JoomlaComment > Content Settings, then on the first tab (General) it's got for the second option "Mambot content function:" - get rid of onPrepareContent and replace it with
onAfterDisplayContent::JOSCusereturn
Daniel, perhaps we should make a FAQ thread (Frequently Asked Questions) in the !JoComment 4.0 subforum and sticky/pin it to the top? We could have things like this here (and other things I remember seeing) for people to try to fix their comment system. I could do this if you like