This bug was reported to Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=613614

I'm using an HP EliteBook 2540p laptop, which contains the Intel Arrandale graphics module with eDP. I use this laptop with an external monitor, which is my major display output and I always shutdown the internal eDP port by running on system start:
# xrandr --output eDP1 --off

However, after that, if I run xrandr query, the eDP1 port will be inadvertently re-enabled, and this ruins my desktop topology since some windows will be randomly thrown over to the eDP1 display that I don't use. The most annoying thing is gnome-screensaver seems invoking xrandr on its every start, perhaps intending to check the monitor settings, and enables the eDP1 port -- so that my monitor topology changes like crazy whenever gnome-screensaver kicks in.

Here's my xrandr output:
$ xrandr 
Screen 0: minimum 320 x 200, current 1680 x 1050, maximum 8192 x 8192
eDP1 connected (normal left inverted right x axis y axis)
   1280x800       60.0 +
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  
VGA1 connected 1680x1050+0+0 (normal left inverted right x axis y axis) 474mm x 296mm
   1680x1050      60.0*+
   1600x1200      60.0  
   1400x1050      60.0  
   1280x1024      75.0     60.0  
   1440x900       59.9  
   1280x960       60.0  
   1152x864       75.0  
   1024x768       75.1     70.1     60.0  
   832x624        74.6  
   800x600        72.2     75.0     60.3     56.2  
   640x480        72.8     75.0     66.7     60.0  
   720x400        70.1  
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)

I'm using the 2.6.37 kernel from Debian experimental or else the eDP port just won't light up.

-- System Information:
Debian Release: wheezy/sid
  APT prefers unstable
  APT policy: (990, 'unstable'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.37-trunk-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages libdrm-intel1 depends on:
ii  libc6                         2.11.2-11  Embedded GNU C Library: Shared lib
ii  libdrm2                       2.4.23-2   Userspace interface to kernel DRM 
ii  libdrm-intel1                 2.4.23-2   Userspace interface to intel-specific kernel DRM services -- runtime
ii  xserver-xorg-video-intel      2:2.14.0-3 X.Org X server -- Intel i8xx, i9xx display driver
ii  linux-image-2.6.37-trunk-amd64 2.6.37-1~experimental.1 Linux 2.6.37 for 64-bit PCs