I have to use your last option, Jim.

Not as much of an issue when I know about how long a thread is from having opened it previously - unless the threads directly above and below it are of similar length. Then I often click on the wrong thread unless I first scroll down to use the bottom of the screen as a line to orient me.

It is apparently not a minor fix as a number of us have noted this over the years. If it were simple to change it, I think Max would have done so already. (The older I get the more often I have trouble clicking on the correct thread that numbers over 50 posts.)   

Another minor inconvenience for the brain-dead - I wonder if there is a simple fix. It would be a nice convenience if the original pm to which one is responding displayed when the reply button is hit so that one doesn't have to go back and forth between reply and "sent messages" to be able to respond. People with functioning memories probably don't have an issue with this:O)