segfault in libQtOpenGL.so when changing display modes

[Adam Porter]

I just upgraded from 4.1.something to 4.2.8 because it was crashing when restoring a saved machine state. Now it often crashes when I switch between Scale and Seamless modes. This was never a problem before upgrading to this version.

It's a Windows XP guest and 2D acceleration is enabled--3D is not.

$ cat /etc/lsb-release 
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=12.10
DISTRIB_CODENAME=quantal
DISTRIB_DESCRIPTION="Ubuntu 12.10"

$ uname -a
Linux hostname 3.5.0-25-generic #39-Ubuntu SMP Mon Feb 25 18:26:58 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

$ apt-cache policy virtualbox-4.2
virtualbox-4.2:
  Installed: 4.2.8-83876~Ubuntu~quantal
  Candidate: 4.2.8-83876~Ubuntu~quantal
  Version table:
 *** 4.2.8-83876~Ubuntu~quantal 0
        100 /var/lib/dpkg/status

$ dmesg
...
device eth0 entered promiscuous mode
VirtualBox[26333]: segfault at 8 ip 00007f402303ccf0 sp 00007fff85a92b48 error 4 in libQtOpenGL.so.4.8.3[7f402300f000+f5000]
device eth0 left promiscuous mode
vboxnetflt: dropped 0 out of 379311 packets

$ apt-cache policy libqt4-opengl
libqt4-opengl:
  Installed: 4:4.8.3+dfsg-0ubuntu3.1
  Candidate: 4:4.8.3+dfsg-0ubuntu3.1
  Version table:
 *** 4:4.8.3+dfsg-0ubuntu3.1 0
        500 http://us.archive.ubuntu.com/ubuntu/ quantal-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ quantal-security/main amd64 Packages
        100 /var/lib/dpkg/status
     4:4.8.3+dfsg-0ubuntu3 0
        500 http://us.archive.ubuntu.com/ubuntu/ quantal/main amd64 Packages

[misha]

Please try disabling the 2D Video Acceleration (on "Display" pabe in VM settings GUI) and see if it solves the crash.