Comment 22 for bug 241145

Binary package hint: xserver-xorg

Ubuntu version is Hardy AMD64.
This is a very strange bug, but very annoying. In an intensive use of Firefox 3 on Flash sites (when Flash is only for ads too) and many opened tabs, X server crashes when closing a Firefox tab by middle mouse button.
Crash is unrecoverable: display goes in text mode and shows latest started deamons and an unmovable graphical mouse cursor (!!!), gdm doesn't restart. The only way to interact with the system is to open a text console with ALT+CTRL+Fx or restart the system by CTRL+ALT+DEL. Mouse cursor is shown in usplash shutdown procedure too.
This is the ending part of Xorg.0.log:

Backtrace:
0: /usr/bin/X(xf86SigHandler+0x6a) [0x48402a]
1: /lib/libc.so.6 [0x7f2960675100]
2: /usr/lib/xorg/modules//libxaa.so [0x7f295dbe4c9c]
3: /usr/lib/xorg/modules//libxaa.so [0x7f295dbe4e96]
4: /usr/bin/X [0x527ea2]
5: /usr/bin/X [0x515c3f]
6: /usr/bin/X(Dispatch+0x2ef) [0x44eaaf]
7: /usr/bin/X(main+0x47d) [0x436b9d]
8: /lib/libc.so.6(__libc_start_main+0xf4) [0x7f29606611c4]
9: /usr/bin/X(FontFileCompleteXLFD+0x279) [0x435ed9]

Fatal server error:
Caught signal 11. Server aborting

(II) AIGLX: Suspending AIGLX clients for VT switch

I've been able to reproduce the bug a couple of times, but only with Compiz enabled.
To try to reproduce the bug open Firefox and go to www.hwupgrade.it (this site has three or so Flash ads). Click many times (about twenty or so) on upper left Home link with middle button (you must open the same home page many times). Let it load for about thirty seconds, if you have a fast connection.
Now click quickly on the left tab with middle button, closing all opened tabs.
In a normal use, bug appear only after an intensive use of Flash enabled sites, particularly if you need to open many tabs with some Flash ads in each page (eg image gallery hostings).

I'm using ATI driver shipping in Hardy (8.47.3).
I think it could be related to nspluginwrapper too.