Try 'less /etc/passwd' within a screen session: the screen is blank. It seems that screen isn't scrolling properly.
More info: after downgrading to screen-3.9.5 the problem goes away.
Bizarrely, a rebuild of 3.9.8 seems to fix the problem.
*** Bug 23200 has been marked as a duplicate of this bug. ***
Fixed in screen-3.9.8-2.