Closing this one, -xinerama has gone with the rewrite of X.org and thanks to 
xrandr multihead works with other mechanisms nowadays.

The -xinerama sadly doesn't work that well in practice. Is there any way how we 
could set up "Virtual" automatically? Any suggestios what we could do here?h

Michael Prokop <mika@grml.org> has uploaded a package that may fix your bug.
Please test the package and inform the maintainer whether
version 0.3.28 of grml-x works as intended or not.

Thank you

The changelog is attached below

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Format: 1.7
Date: Thu, 12 Jul 2007 01:20:52 +0200
Source: grml-x
Binary: grml-x
Architecture: source all
Version: 0.3.28
Distribution: unstable
Urgency: low
Maintainer: Michael Prokop <mika@grml.org>
Changed-By: Michael Prokop <mika@grml.org>
Description: 
 grml-x     - wrapper for startx for running X Window System
Changes: 
 grml-x (0.3.28) unstable; urgency=low
 .
   * Initial support for Xinemera setup using -xinerama option.
     Added 'bc' to Depends. [Testing: issue241]
   * Support activating composite extension on cmdline using
     the -composite option. (By default it's deactivated.)
   * Remove some blank lines in generated xorg.conf.
   * Switch from manually written nroff manpage to asciidoc
     instead. Adjusted Build-Depends therefore (asciidoc, xsltproc,
     docbook-xsl). The manual page is available online as well now:
     http://grml.org/grml-x/
Files: 
 0ecf6ba9a7d6578a27870fbe7a455338 519 grml optional grml-x_0.3.28.dsc
 b0a785570b28d19b4bb34c734764edad 22238 grml optional grml-x_0.3.28.tar.gz
 8d7da5529dd2959ac09ff1d65761078a 22158 grml optional grml-x_0.3.28_all.deb

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'hwinfo --framebuffer' seems to do the trick for use:

 hwinfo --framebuffer
02: None 00.0: 11001 VESA Framebuffer
  [Created at bios.447]
  Unique ID: rdCR.5WU5JOR4rxD
  Hardware Class: framebuffer
  Model: "Intel(r)915GM/910ML/915MS Graphics Chip Accelerated VGA BIOS 
Intel(r)915GM/910ML/915MS Graphics Controller"
  Vendor: "Intel Corporation"
  Device: "Intel(r)915GM/910ML/915MS Graphics Controller"
  SubVendor: "Intel(r)915GM/910ML/915MS Graphics Chip Accelerated VGA BIOS"
  SubDevice:
  Revision: "Hardware Version 0.0"
  Memory Size: 7 MB + 704 kB
  Memory Range: 0xc0000000-0xc07affff (rw)
  Mode 0x033c: 1400x1050 (+1408), 8 bits
  Mode 0x034d: 1400x1050 (+2816), 16 bits
  Mode 0x035c: 1400x1050 (+5632), 24 bits
  Mode 0x0307: 1280x1024 (+1280), 8 bits
  Mode 0x031a: 1280x1024 (+2560), 16 bits
  Mode 0x031b: 1280x1024 (+5120), 24 bits
  Mode 0x0305: 1024x768 (+1024), 8 bits
  Mode 0x0317: 1024x768 (+2048), 16 bits
  Mode 0x0318: 1024x768 (+4096), 24 bits
  Mode 0x0312: 640x480 (+2560), 24 bits
  Mode 0x0314: 800x600 (+1600), 16 bits
  Mode 0x0315: 800x600 (+3200), 24 bits
  Mode 0x0301: 640x480 (+640), 8 bits
  Mode 0x0303: 800x600 (+832), 8 bits
  Mode 0x0311: 640x480 (+1280), 16 bits
  Config Status: cfg=new, avail=yes, need=no, active=unknown
root@meilenschwein ~ #

-> working on that....

Problem:

# hwinfo --monitor
31: None 00.0: 10000 Monitor
  [Created at monitor.93]
  Unique ID: rdCR.OYGIo1r6D00
  Hardware Class: monitor
  Model: "SAMSUNG SyncMaster"
  Vendor: SAM "SAMSUNG"
  Device: eisa 0x027e "SyncMaster"
  Serial ID: "HS3P516457"
  Resolution: 720x400@70Hz
  Resolution: 640x480@60Hz
  Resolution: 640x480@67Hz
  Resolution: 640x480@72Hz
  Resolution: 640x480@75Hz
  Resolution: 800x600@56Hz
  Resolution: 800x600@60Hz
  Resolution: 800x600@72Hz
  Resolution: 800x600@75Hz
  Resolution: 832x624@75Hz
  Resolution: 1024x768@60Hz
  Resolution: 1024x768@70Hz
  Resolution: 1024x768@75Hz
  Resolution: 1280x1024@75Hz
  Resolution: 1280x1024@60Hz
  Resolution: 1280x960@60Hz
  Resolution: 1152x864@75Hz
  Resolution: 1680x1050@60Hz
  Size: 474x296 mm
  Detailed Timings:
     Resolution: 1680x1050
     Horizontal: 1680 1728 1760 1840 (+48 +80 +160) -hsync
       Vertical: 1050 1053 1059 1080 (+3 +9 +30) +vsync
    Frequencies: 119.00 MHz, 64.67 kHz, 59.88 Hz
  Driver Info #0:
    Max. Resolution: 1680x1050
    Vert. Sync Range: 56-75 Hz
    Hor. Sync Range: 30-81 kHz
    Bandwidth: 119 MHz
  Config Status: cfg=new, avail=yes, need=no, active=unknown
root@meilenschwein ~ #

mika@meilenschwein ~ % hwinfo --monitor
29: None 00.0: 10000 Monitor
  [Created at fb.71]
  Unique ID: rdCR.EY_qmtb9YY0
  Hardware Class: monitor
  Model: "Generic Monitor"
  Vendor: "Generic"
  Device: "Monitor"
  Resolution: 1280x1024@77Hz
  Driver Info #0:
    Max. Resolution: 1280x1024
    Vert. Sync Range: 50-90 Hz
    Hor. Sync Range: 31-82 kHz
  Config Status: cfg=new, avail=yes, need=no, active=unknown
mika@meilenschwein ~ %

Wheras the information from user root is correct for the *external* monitor, 
the information you retrieve when running as normal user is just wrong. I 
didn't find a way to get information of *both* monitors without running 'hwinfo 
--all' which sucks because several systems have problems (like kernel crash) 
when running that....

Current intel drivers provide nice hotplugging and multihead support nearly 
OOTB. Would be great if we could generate the appropriate Virtual line in 
xorg.conf without any further manual input.