What about byobu built on top of tmux? Isn't it more straightforward?
The other thing I didn't care w/byobu was that it had a clock in the bottom row. Once a minute my terminal window would light up telling me that something on that tab had changed.
If I have the time, though, I'll fire up byobu and see if I can make it happen again. I tend to leave sessions open for many months and it wasn't something which happened on a regular basis, and I never experienced it with bare tmux.