Window titles often remain displayed after closing parent window

[Peter Roos]

Most of the time Unity works as expected, that is, it displays the topmost window's title. Sometimes, however, and in my experience, only when there are no more windows after closing the last one, the title stays there. I've attached a screen shot of this bug, in which one can see that I had closed QtCreator, and instead of Ubuntu Desktop, QtCreator is still showed as current window title (although it's greyed out). I'm using the 'Show the menus for a window : in the window's title bar' appearance option.

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: unity 7.3.2+15.10.20151016-0ubuntu1
ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
Uname: Linux 4.2.0-16-generic x86_64
NonfreeKernelModules: nvidia
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 352.63 Sat Nov 7 21:25:42 PST 2015
 GCC version: gcc version 5.2.1 20151010 (Ubuntu 5.2.1-22ubuntu2)
ApportVersion: 2.19.1-0ubuntu5
Architecture: amd64
BootLog:

CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CurrentDesktop: Unity
Date: Thu Nov 19 10:09:16 2015
DistUpgraded: Fresh install
DistroCodename: wily
DistroVariant: ubuntu
DkmsStatus:
 bbswitch, 0.7, 4.2.0-16-generic, x86_64: installed
 nvidia-352, 352.63, 4.2.0-16-generic, x86_64: installed
 nvidiabl, 0.88, 4.2.0-16-generic, x86_64: installed
 virtualbox, 5.0.4, 4.2.0-16-generic, x86_64: installed
GraphicsCard:
 NVIDIA Corporation GF108GLM [Quadro 1000M] [10de:0dfa] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: Hewlett-Packard Company Device [103c:1631]
InstallationDate: Installed on 2015-10-23 (26 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
MachineType: Hewlett-Packard HP EliteBook 8560w
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-16-generic root=UUID=1702774b-5cce-4e3b-8cad-c15f2e95450a ro acpi_backlight=vendor quiet splash
SourcePackage: unity
UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/12/2015
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: 68SVD Ver. F.60
dmi.board.name: 1631
dmi.board.vendor: Hewlett-Packard
dmi.board.version: KBC Version 01.3F
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnHewlett-Packard:bvr68SVDVer.F.60:bd03/12/2015:svnHewlett-Packard:pnHPEliteBook8560w:pvrA0001D02:rvnHewlett-Packard:rn1631:rvrKBCVersion01.3F:cvnHewlett-Packard:ct10:cvr:
dmi.product.name: HP EliteBook 8560w
dmi.product.version: A0001D02
dmi.sys.vendor: Hewlett-Packard
version.compiz: compiz 1:0.9.12.2+15.10.20151015-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.64-1
version.libgl1-mesa-dri: libgl1-mesa-dri 11.0.2-1ubuntu4
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 11.0.2-1ubuntu4
version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.17.2-1ubuntu9
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.2-1ubuntu1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.5.0+git20150819-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20150808-0ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu3
xserver.bootTime: Thu Nov 19 07:31:15 2015
xserver.configfile: default
xserver.errors: open /dev/fb0: No such file or directory
xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:

xserver.version: 2:1.17.2-1ubuntu9