Forum replies are not visible to guest users
If you are not logged in you can see the first post to forums, but you can't see subsequent posts. Somewhere there is a permissions problem.
Is a forum reply a "comment"? It appears that Drupal is locking out blog comments for guests as well...
[b]Update:[/b] Yep. That was it. Anonymous users need to be able to view comments.
How can I set my blog to allow commenting by default?