with gdb o got this:
gdb 04
GNU gdb (GDB; openSUSE 11.1) 6.8.50.20081120-cvs
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-suse-linux".
For bug reporting instructions, please see:
<http://bugs.opensuse.org/>...
(gdb) run
Starting program: /home/xpete/qgis/disko-tutorials/firststeps/04/04
[Thread debugging using libthread_db enabled]

**** * *** * * ***
* * * * * * * *
* * * *** ** * *
* * * * * * * *
**** * *** * * *** V1.5
----------------------------------------------------------------------
The Linux application framework for embedded devices.

Copyright (C) 2005-2007 Stefan Schwarzer, Jens Schneider,
Matthias Hardt, Guido Madaus
Copyright (C) 2007-2008 Berlinux Solutions GbR
Stefan Schwarzer & Guido Madaus
----------------------------------------------------------------------
ConfigDB: ./configdb ()
DataDB: ./datadb ()
Logfile: ./logfile
First plugin:
Input map: default
Prefix: ./
Theme:
Resolution: 800x600
Backend:
Output type: X11
Video layer id: 0
Video layer pixelformat: RGB32
Video layer options:
Video layer buffermode: BACKSYSTEM
Graphics layer id: 0
Graphics layer pixelformat: RGB32
Graphics layer options:
Graphics layer buffermode: BACKSYSTEM
Visible screen area: 0,0,800,600
Log to stdout: no
Input Interval: 0 ms
Input Mode:
Call shutdown command: no
Shutdown command:
Touch pad/screen area: 0,0,0,0
Show mouse pointer: TRUE
Graphics window pixelformat: ARGB
Graphics surface pixelformat: ARGB
Extended acceleration: yes
Alloc Method: MALLOC
Fullscreen: FALSE
Sourcelanguage: ukn
Targetlanguage: ukn
Add missing translations: no
----------------------------------------------------------------------
Starting Disko Tutorial: firststeps/04...
w: 1680, h: 1050
DISKO: Available xv adaptors:
NV17 Video Texture (used)
DISKO: Using accelerated fill rectangle to YV12.
[New Thread 0x7ffff0865b90 (LWP 18287)]
DISKO: Pixelformat ARGB is used for surfaces.
[New Thread 0x7ffff059c950 (LWP 18288)]
[New Thread 0x7fffefd9b950 (LWP 18289)]
[Thread 0x7fffefd9b950 (LWP 18289) exited]
[Thread 0x7ffff059c950 (LWP 18288) exited]
DISKO: Pixelformat ARGB is used for windows with alphachannel.
[New Thread 0x7fffef1efb90 (LWP 18290)]
[New Thread 0x7fffef0fab90 (LWP 18291)]
[New Thread 0x7fffeefbab90 (LWP 18292)]
DISKO: Using accelerated fill rectangle to ARGB.
DISKO: Using accelerated copy ARGB to ARGB.
DISKO: Using accelerated blend ARGB to YV12.
[Thread 0x7fffef1efb90 (LWP 18290) exited]
[New Thread 0x7fffef1efb90 (LWP 18293)]
DISKO: Using accelerated blend ARGB to ARGB.
[Thread 0x7fffef1efb90 (LWP 18293) exited]
[Thread 0x7fffeefbab90 (LWP 18292) exited]
[New Thread 0x7fffeefbab90 (LWP 18341)]
DISKO: Using accelerated blend rectangle to ARGB.
DISKO: Using blend text ARGB.
DISKO: Using accelerated copy YV12 to YV12.
DISKO: Using accelerated blend coloralpha ARGB to YV12.
[Thread 0x7fffeefbab90 (LWP 18341) exited]
[New Thread 0x7fffeefbab90 (LWP 18360)]
[New Thread 0x7fffef1efb90 (LWP 18361)]
[Thread 0x7fffeefbab90 (LWP 18360) exited]
[Thread 0x7fffef1efb90 (LWP 18361) exited]
[New Thread 0x7fffef1efb90 (LWP 18362)]
[New Thread 0x7fffeefbab90 (LWP 18363)]
[Thread 0x7fffef1efb90 (LWP 18362) exited]
[Thread 0x7fffeefbab90 (LWP 18363) exited]
[New Thread 0x7fffeefbab90 (LWP 18411)]
DISKO: Using accelerated blend coloralpha ARGB to ARGB.
[Thread 0x7fffeefbab90 (LWP 18411) exited]
[New Thread 0x7fffeefbab90 (LWP 18430)]
[Thread 0x7fffeefbab90 (LWP 18430) exited]
[New Thread 0x7fffeefbab90 (LWP 18433)]
[Thread 0x7fffeefbab90 (LWP 18433) exited]
[New Thread 0x7fffeefbab90 (LWP 18481)]
[Thread 0x7fffeefbab90 (LWP 18481) exited]
[New Thread 0x7fffeefbab90 (LWP 18500)]
[Thread 0x7fffeefbab90 (LWP 18500) exited]
[New Thread 0x7fffeefbab90 (LWP 18501)]
[Thread 0x7fffeefbab90 (LWP 18501) exited]
[New Thread 0x7fffeefbab90 (LWP 18551)]
[Thread 0x7fffeefbab90 (LWP 18551) exited]
[New Thread 0x7fffeefbab90 (LWP 18570)]
[Thread 0x7fffeefbab90 (LWP 18570) exited]
[New Thread 0x7fffeefbab90 (LWP 18571)]
[Thread 0x7fffeefbab90 (LWP 18571) exited]
[New Thread 0x7fffeefbab90 (LWP 18620)]
[Thread 0x7fffeefbab90 (LWP 18620) exited]
[New Thread 0x7fffeefbab90 (LWP 18639)]
[Thread 0x7fffeefbab90 (LWP 18639) exited]
[New Thread 0x7fffeefbab90 (LWP 18640)]
[Thread 0x7fffeefbab90 (LWP 18640) exited]
[New Thread 0x7fffeefbab90 (LWP 18688)]
[Thread 0x7fffeefbab90 (LWP 18688) exited]
[New Thread 0x7fffeefbab90 (LWP 18707)]
[Thread 0x7fffeefbab90 (LWP 18707) exited]
[New Thread 0x7fffeefbab90 (LWP 18708)]
[Thread 0x7fffeefbab90 (LWP 18708) exited]
[New Thread 0x7fffeefbab90 (LWP 18756)]
[Thread 0x7fffeefbab90 (LWP 18756) exited]
[New Thread 0x7fffeefbab90 (LWP 18775)]
[Thread 0x7fffeefbab90 (LWP 18775) exited]
[New Thread 0x7fffeefbab90 (LWP 18776)]
[Thread 0x7fffeefbab90 (LWP 18776) exited]
[New Thread 0x7fffeefbab90 (LWP 18824)]
[Thread 0x7fffeefbab90 (LWP 18824) exited]
[New Thread 0x7fffeefbab90 (LWP 18843)]
[Thread 0x7fffeefbab90 (LWP 18843) exited]
[New Thread 0x7fffeefbab90 (LWP 18844)]
[Thread 0x7fffeefbab90 (LWP 18844) exited]
[New Thread 0x7fffeefbab90 (LWP 18894)]
[Thread 0x7fffeefbab90 (LWP 18894) exited]
[New Thread 0x7fffeefbab90 (LWP 18913)]
[Thread 0x7fffeefbab90 (LWP 18913) exited]
[New Thread 0x7fffeefbab90 (LWP 18914)]
[Thread 0x7fffeefbab90 (LWP 18914) exited]
[New Thread 0x7fffeefbab90 (LWP 18962)]
[Thread 0x7fffeefbab90 (LWP 18962) exited]
[New Thread 0x7fffeefbab90 (LWP 18981)]
[Thread 0x7fffeefbab90 (LWP 18981) exited]
[New Thread 0x7fffeefbab90 (LWP 18982)]
[Thread 0x7fffeefbab90 (LWP 18982) exited]
[New Thread 0x7fffeefbab90 (LWP 19030)]
[Thread 0x7fffeefbab90 (LWP 19030) exited]
[New Thread 0x7fffeefbab90 (LWP 19049)]
[Thread 0x7fffeefbab90 (LWP 19049) exited]
[New Thread 0x7fffeefbab90 (LWP 19050)]
[Thread 0x7fffeefbab90 (LWP 19050) exited]
[New Thread 0x7fffeefbab90 (LWP 19098)]
[Thread 0x7fffeefbab90 (LWP 19098) exited]
[New Thread 0x7fffeefbab90 (LWP 19117)]
[Thread 0x7fffeefbab90 (LWP 19117) exited]
XIO: fatal IO error 11 (Resource temporarily unavailable) on X server ":0.0"
after 581 requests (407 known processed) with 2 events remaining.
[Thread 0x7fffef0fab90 (LWP 18291) exited]
[Thread 0x7ffff0865b90 (LWP 18287) exited]

Program exited with code 01.
(gdb)

I hope it's useful.

Hi xpete,

I didn't follow the whole thread, so maybe it was already mentioned.
Which graphics card do you use? The reason for asking this is, that
it looks like the X-server is dumping. We had the same problem until
today and it was a bug in the Intel video driver, which was fixed
yesterday with the release of 2.7.0.
So if you're using an Intel chipset, you should consider updating.

Best regards,
Matthias

Nvidia Geforce 9700m GT with nvidia driver version: 185.19 beta...
i will try with 180.51 that is "stable" but i doubt that it works better.

with version 180.51 the problem remains.