Redisplay problems with intel driver

[Tassilo Horn]

Hello all,

I use the xorg-server 1.5.0 (but had this problem with 1.4.2, too)
together with the free intel driver (2.4.2) on a IBM/Lenovo ThinkPad T61
which has an Intel X3100 card.

Since one or two weeks I have some very strange redisplay problems.

  - I close a window, but it's still displayed.  When I move another
    window over it, it'll be erased.  (It's like cleaning a chalkboard.)

  - I follow a link in a webbrowser, but the old page is still
    displayed.  In order to see the new one, I have to move the window.

  - I compile something in a terminal and some lines are not refreshed.
    Again, moving the window forces a redisplay.

It seems to be not depended on the applications I use.  It always
happens with konqueror, urxvt, emacs, firefox running inside stumpwm or
XFCE.  But till now I didn't have these problems when running inside KDE
4.1.

I'm not completely sure since when these problems occur, but I assume
it's since I updated the intel driver from 2.4.1 to 2.4.2.

These problems only occur, if I have no second monitor attached!  At
work, I use my laptop lcd as second monitor left of a big additional
tft.  Then redisplay I allright.

I run this simple script on in my ~/.xinitrc to set up the outputs.

--8<---------------cut here---------------start------------->8---
#!/bin/zsh

ORIENTATION=${argv[1]}
if [[ -z ${ORIENTATION} ]]; then
    ORIENTATION='--right-of'
fi

SECOND_OUTPUT=`xrandr \
    | egrep "[[:alnum:]]+ connected" \
    | grep --invert-match "LVDS" \
    | cut --d " " -f1`

if [[ -n ${SECOND_OUTPUT} ]]
then
    xrandr --auto
    xrandr --output ${SECOND_OUTPUT} ${ORIENTATION} LVDS
    if [[ ${SECOND_OUTPUT} == TMDS-1 ]]; then
        xrandr --output ${SECOND_OUTPUT} --mode 1920x1200
    fi
    echo "Enabled second output ${SECOND_OUTPUT} ${ORIENTATION} of laptop LCD."
else
    xrandr --auto
    echo "There's no second monitor attached."
fi

xrandr --dpi 96

echo "Finito."
--8<---------------cut here---------------end--------------->8---

What additional information can I provide?

I'll try to downgrade to intel driver 2.4.1 to see if that helps and
report back.  Hopefully I'll find some time this evening.

Bye,
Tassilo