>I'd really like it if the "Next" link under the message worked until there were no more messages. As it is I have to go back up to the top frame. Find where I was, then click on the next message. It's really a pain.

This has been discussed and discussed all over again. Some want it like that, some want it as is. The next link has the behavior to get the next messages in regards to the current message. If it has no reply, it is not linked. There is nothing more to add here. What you want is the ability to skip to the next branch if there is no reply. That is not supported at this moment.