Created attachment 28677 [details]
Dmesg excerpt.

Hello:

I've tried running konqueror with Qt opengl graphic acceleration, like this: konqueror -graphicssystem=opengl

I'm on Debian sid with self build Linux 2.6.30.4 UMS, KDE 4.3, Qt4.5.2, intel driver 2.8.0, drm 2.4.12, mesa 7.5, xserver 1.6.3

$ lspci -vnn -s 2.0
00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller [8086:2a02] (rev 03) (prog-if 00 [VGA controller])
        Subsystem: Toshiba America Info Systems Device [1179:ff50]
        Flags: bus master, fast devsel, latency 0, IRQ 28
        Memory at f0000000 (64-bit, non-prefetchable) [size=1M]
        Memory at d0000000 (64-bit, prefetchable) [size=256M]
        I/O ports at 1800 [size=8]
        Expansion ROM at <unassigned> [disabled]
        Capabilities: <access denied>

After loading konqueror I noticed the application behaved slightly different with appearing white boxes on the rendering area when I tried to load this url: http://www.publico.es it loaded. When it was about to end it was when Xorg was unusable, yet the mouse pointed moved.

Doing ssh from another machine I got the attached dmesg excerpt. Xorg log showed nothing interesting. 

Xorg trace was normal:
#0  0x00007faea7b204a7 in ioctl () from /lib/libc.so.6
#1  0x00007faea6714673 in drmIoctl (fd=8, request=25688, arg=0x0) at ../../libdrm/xf86drm.c:188
#2  0x00007faea6714976 in drmCommandNone (fd=8, drmCommandIndex=<value optimized out>) at ../../libdrm/xf86drm.c:2344
#3  0x00007faea628f440 in I830BlockHandler (i=<value optimized out>, blockData=0x0, pTimeout=0x7fffe744b1d8, pReadmask=0x7d67a0)
    at ../../src/i830_driver.c:2228
#4  0x0000000000531248 in AnimCurScreenBlockHandler (screenNum=0, blockData=0x0, pTimeout=0x7fffe744b1d8, pReadmask=0x7d67a0)
    at ../../render/animcur.c:222
#5  0x00000000004fd4ce in compBlockHandler (i=0, blockData=0x0, pTimeout=0x7fffe744b1d8, pReadmask=0x7d67a0)
    at ../../composite/compinit.c:158
#6  0x0000000000450cd0 in BlockHandler (pTimeout=0x7fffe744b1d8, pReadmask=0x7d67a0) at ../../dix/dixutils.c:384
#7  0x00000000004ebb51 in WaitForSomething (pClientsReady=0x4a2e760) at ../../os/WaitFor.c:215
#8  0x000000000044d060 in Dispatch () at ../../dix/dispatch.c:367
#9  0x000000000043329a in main (argc=8, argv=0x7fffe744b3b8, envp=<value optimized out>) at ../../dix/main.c:397

intel_gpu_dump was way short:
ACTHD: 0x093fd2c0
EIR: 0x00000000
EMR: 0xffffffdf
ESR: 0x00000011
IPEHR: 0x60020100
Ringbuffer: Reminder: head pointer is GPU read, tail pointer is CPU write

Closedly related bugs I've seen are http://bugs.freedesktop.org/show_bug.cgi?id=23032 (for different HW) and http://bugs.freedesktop.org/show_bug.cgi?id=22336 (not sure wether the exact same problem).