Firefox running and not responding

[GuiUbuntu]

Binary package hint: firefox-3.0

Mensage: '' Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system'' He have problem and closed window.

ProblemType: Bug
Architecture: amd64
DistroRelease: Ubuntu 8.10
NonfreeKernelModules: nvidia ath_hal
Package: firefox-3.0 3.0.11+build2+nobinonly-0ubuntu0.8.10.1
ProcEnviron:
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
 LANG=fr_CH.UTF-8
 SHELL=/bin/bash
SourcePackage: firefox-3.0
Uname: Linux 2.6.27-14-generic x86_64

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Franck Arnaud (franck-nenie)]

In my case firefox when firefox is stuck with no visible window but a zombie process (as happens every so often for unknown reasons) I also get this message.

Via xlsclient I do find a firefox 10x10 pixels unmapped window that is not visible anywhere (the Unity dock doesn't find it either). The output of xwininfo is attached.

The user interaction design is very poor: in this case the dialog should either:

(a) offer a "kill and retry" button
(b) detect the hung firefox and do a kill and retry silently, counting the retries to avoid an endless retry loop, and only when that procedure has failed show the dialog

there is in this case no reason to force the user to "restart the system" to emulate the mediocrity of the Windows user experience.

xwininfo: Window id: 0x1800001 "Firefox"

  Absolute upper-left X: 10
  Absolute upper-left Y: 10
  Relative upper-left X: 10
  Relative upper-left Y: 10
  Width: 10
  Height: 10
  Depth: 24
  Visual: 0x20
  Visual Class: TrueColor
  Border width: 0
  Class: InputOutput
  Colormap: 0x22 (installed)
  Bit Gravity State: NorthWestGravity
  Window Gravity State: NorthWestGravity
  Backing Store State: NotUseful
  Save Under State: no
  Map State: IsUnMapped
  Override Redirect State: no
  Corners: +10+10 -1900+10 -1900-1180 +10-1180
  -geometry 10x10+10+10