I forgot:

xserver-xorg-video-intel: 2:2.8.1+git20090829.7c48c21b
kernel: 2.6.31-999.200909011000

With LIBGL_ALWAYS_SOFTWARE=1 everything renders correctly.

Also, it seems there is a memory leak involved. After seeing the black blender while scrolling a menu up and down, memory usage in top goes up by 80MB!
After using blender for 5 minutes memory usage is at 700MB of 700MB and swap
is at 600MB of 900MB.

I can reproduce this on 915GM, while GM965 is fine.

Good news: After updating libgl1-mesa-dri 
to 7.7.0~git20090910.18882f4d-0ubuntu0tormod~jaunty
black menus and memory leak are gone.

Bad news: Blender segfaults now when accessing the menu! :(

GDB backtrace:

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb64796e0 (LWP 4724)]
0x00000000 in ?? ()
(gdb) bt
#0  0x00000000 in ?? ()
#1  0xb609130a in _swrast_ReadPixels () from /usr/lib/dri/i915_dri.so
#2  0xb5f640e9 in intelReadPixels () from /usr/lib/dri/i915_dri.so
#3  0xb600a7b6 in _mesa_ReadPixels () from /usr/lib/dri/i915_dri.so
#4  0x083ffeeb in ?? ()
#5  0x084079ad in uiDoBlocks ()
#6  0x083d7705 in screenmain ()
#7  0x081aa5d5 in main ()

Mesa demos and openarena work fine.

INTEL_DEBUG=pix blender tells:

intelCopyPixels
do_blit_copypixels: success
intelReadPixels
do_blit_readpixels
do_blit_readpixels - not PBO
intelReadPixels: fallback to swrast
Segmentation fault

glinfo shows:
GL_ARB_pixel_buffer_object

It seems that pixel buffer objects are advertised but there is none.

Gordon and Gonz,

What versions of everything are you using?  If I use current xf86-video-intel, xserver, Mesa, and kernel, I am not able to reproduce any of these problems.  If I mix newer Mesa with the F11 Intel driver (2.7.0) and xserver (1.6.3), I am able to produce several problems, but not these.

Ian,

> What versions of everything are you using?  If I use current xf86-video-intel,
> xserver, Mesa, and kernel, I am not able to reproduce any of these problems. 
> If I mix newer Mesa with the F11 Intel driver (2.7.0) and xserver (1.6.3), I am
> able to produce several problems, but not these.

xf86-video-intel: 2:2.8.1+git20090907.94fc93d4-0ubuntu0tormod~jaunty
xserver: 2:1.6.3+git20090805+server-1.6-branch.f274e595-0ubuntu0sarvatt3~jaunty
libgl1-mesa-dri: 7.7.0~git20090910.18882f4d-0ubuntu0tormod~jaunty
kernel:  2.6.31-999.200909011000

This is Ubuntu Jaunty with a kernel from
http://kernel.ubuntu.com/~kernel-ppa/mainline/
and xserver, mesa and intel driver from
https://edge.launchpad.net/~xorg-edgers/+archive/ppa
. 

Maybe it's one of Ubuntu's patches.
I have intel-gpu-tools installed, so if I can help narrow it down...

(In reply to comment #7)
> Gordon and Gonz,
> 
> What versions of everything are you using?  If I use current xf86-video-intel,
> xserver, Mesa, and kernel, I am not able to reproduce any of these problems. 
> If I mix newer Mesa with the F11 Intel driver (2.7.0) and xserver (1.6.3), I am
> able to produce several problems, but not these.
> 

I reproduced this with following commits in Q3-RC1 build (around Sep 1st):
Libdrm: (master)73b59c894380995a2889b98e79acadd2da0bb237
Mesa: (master)8126dfa9c24c972794193bf652d6d09a1d01b376
Xserver: (server-1.6-branch)3044711412d0a08ba65a491bd2441c0c8980f5e2
Xf86_video_intel: (master)5812531e08147576de776b2dd64e7f94c08eb851
Kernel: (master) 326ba5010a5429a5a528b268b36a5900d4ab0eba

With latest mesa_7_6_branch, it works fine.

With latest mesa master branch, I get segfault(bug#23862).

So I think this issue has been fixed.

Running master d3f5a2 this is fixed. I believe (but did not test) that it was fixed in 8ec45.