output to background nested screen stops until foregrounded

[Aaron Davies]

my typical setup is a nested screen--one screen session running on a box, call 
it box1, holding five windows, each running an ssh to a different box, call 
them box1 through box5, each of which runs screen again. most of the inner 
screens will have at least one window running a process that continuously 
produces output (something running inside `watch', a `tail -f', etc.).

if i leave that window as the current window on that screen, then switch away 
from that on the outer screen, and leave things that way for a long time (e.g. 
overnight, about eight hours), then when i go back to that screen, i find it 
hasn't updated in hours (the clock in the caption line shows a time well into 
the past). when i begin to issue any screen command (just hitting C-a a to send 
the command char to the inner screen is sufficient) it starts outputting all 
the updates in rapid succession. if there are a lot of them (e.g. if it was 
running `watch' on its default setting of "update every two seconds"), this can 
take several minutes to finish.

how can i change this? i'd like to have inner screens continue to redraw 
themselves whether or not they're currently visible in the outer screen.
-- 
Aaron Davies
address@hidden