Lenovo Thinkpad 410s Intel problem with rotated display on minidock dvi: xterm output is only flushed when I press button on the keyboard

[Thomas Glanzmann]

Hello Xorg List,
I have Lenovo t410s with a Intel graphic card running debian squeeze
(this problem happens with the debian squeeze intel driver and the one
from backports). I have a rotated display on the minidock dvi port. When
my xterm generates any output after I pressed a key, the output is not
shown on my screen until I press a key on the keyboard (mouse button is
not sufficient. When I paste something in my xterm is also only appears
as soon as I press a key on the keyboard. Do you have any idea how I get
rid of this problem?

00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 02)
00:02.0 0300: 8086:0046 (rev 02)

http://upload.glanzmann.de/Xorg.0.log

I also wonder about the following:

When I start X ist comes up with 1024x768, but I can resize it using xrandr to
1600x1200 and than rotate it counter clockwise using xrandr -o 1. I tried to
generate an xorg.conf by myself using Xorg -configure which only shows me a
blank screen. You can find that config here:

http://upload.glanzmann.de/xorg.conf.new

Cheers,
        Thomas