triangle in unity launcher missed for multiple windows

[Guiodic (Guido Iodice)]

how to reproduce:
1. click on "file" icon in unity launcher
2. right-click on file icon in unity launcher and select a folder (for example: documents)

what actually happens:
only a triangle on the left of file icon in the launcher (see 1st screenshot)

what should happen:
2 triangle on the left of file icon in the launcher

but:
If you click on file icon in the laucher, two triangles appear (see second screenshot)

but:
if you close a nautilus windows the 2 triangles are still there

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: unity 7.1.2+14.04.20140320.1-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-19.39-generic 3.13.6
Uname: Linux 3.13.0-19-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.13.3-0ubuntu1
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Sat Mar 22 19:54:25 2014
DistUpgraded: Fresh install
DistroCodename: trusty
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Hewlett-Packard Company Device [103c:18fe]
InstallationDate: Installed on 2014-02-22 (27 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140222)
MachineType: Hewlett-Packard HP Pavilion Sleekbook 15
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-19-generic.efi.signed root=UUID=122fd8d4-4976-4d71-ba82-32a0c539ac79 ro quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/02/2012
dmi.bios.vendor: Insyde
dmi.bios.version: F.12
dmi.board.asset.tag: Type2 - Board Asset Tag
dmi.board.name: 18FE
dmi.board.vendor: Hewlett-Packard
dmi.board.version: 82.23
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnInsyde:bvrF.12:bd11/02/2012:svnHewlett-Packard:pnHPPavilionSleekbook15:pvr087D1100003B5900000320100:rvnHewlett-Packard:rn18FE:rvr82.23:cvnHewlett-Packard:ct10:cvrChassisVersion:
dmi.product.name: HP Pavilion Sleekbook 15
dmi.product.version: 087D1100003B5900000320100
dmi.sys.vendor: Hewlett-Packard
version.compiz: compiz 1:0.9.11+14.04.20140320.1-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.52-1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.1.0-1ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.1.0-1ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.15.0-1ubuntu7
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.8.2-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.3.0-1ubuntu3
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.910-0ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.10-1ubuntu2
xserver.bootTime: Sat Mar 22 19:42:09 2014
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 14681
 vendor SEC
xserver.version: 2:1.15.0-1ubuntu7