Mousewheel scroll after window switch?

[chiasa.men]

Example:
screenrc contains: termcapinfo xterm* ti@:te@

screen
for i in {1..200}; do echo $i a; done
# open new window, ctrl + a n
for i in {1..200}; do echo $i b; done
# switch back, ctrl + a a
# scroll back with mouse wheel

The text at the top will (besides of numbers) look like:
142 b
143 a

In copy mode with pg up/dwn it works as expected.
Is there any way to scroll within a screen window?