Crash when opening any page that uses windowless plugins with graphicssytem opengl.
Changing platform to Linux :-)
This is a Qt bug. Nothing much I can do other than fix Qt.
Situation much better with b5efa250a6706821cf9969752a8fd063d1f206d6 in Qt 4.6 branch. Still spurious crashes, but happens now and then.
Now that the Qt bug tracker is open, I will close this and open a bug there.