Thank you! I have been using screen for 2 years and wanted to know how to fix this, but never knew what phrase to google to see if there was a fix. Every time I would background emacs (^z) it would clobber all of my previous console output so I would have to re-grep things, for example.
In return I give you my favorite screen hack that displays the available RAM on the server every 30 seconds in the caption:
In ~/.screenrc
backtick 2 30 30 $HOME/.screenrc.bt.2
caption always "%{gk}plab001 %?%{wk}%-Lw%?%{yK}%n*%f %t%?(%u)%?%?%{wk}%+Lw%? %=%{yk}%2` %{gk}%c %{yk}%d/%M/%Y"
in ~/.screenrc.bt.2
free -m | xargs | awk '{print $17 "MB"}'
The caption string above also prints the current window titles and the time/date, so this is also useful for keeping ssh sessions open indefinitely since there is activity at least once a minute when the time updates.