Seeing as the system used to display wether there are new comments or not is a bit.. well flaky. Could the order of the messages be in order of last activity? Somewhat like it is on a real forum? The one with the most recent comments are placed at the top.

Just set up a basecamp account for our school parents association and they love it. The biggest request has been for the message list to be ordered based on most recent activity.

Please think about adding this.