O problema atual aconteceu comigo pela segunda vez (última vez que eu reinstalei todo o Ubuntu para resolvê-lo) Atualmente estou usando o Ubuntu 14.04 com o Gnome Fiz algumas atualizações usando o Software Updater e perdi vários ícones no menu de aplicativos (se eu alterar o tema usando a Tweak Tool, recebo-os de volta, mas a cada reinicialização alguns ícones estão desaparecendo novamente).
A atualização afetou esses pacotes:
Start-Date: 2015-03-01 17:21:45
Commandline: aptdaemon role='role-commit-packages' sender=':1.264'
Install: libllvm3.6:amd64 (3.6~+rc2-2ubuntu1~xedgers14.04.1)
Upgrade: e2fslibs:amd64 (1.42.9-3ubuntu1, 1.42.9-3ubuntu1.2), xserver-xorg-video-vmware:amd64 (13.0.2-2ubuntu1, 13.0.2+git20140804.0a596fd0-0ubuntu0sarvatt~trusty), intel-gpu-tools:amd64 (1.3-0ubuntu2.1, 1.8-1~xedgers~trusty), libegl1-mesa:amd64 (10.1.3-0ubuntu0.3, 10.5.0~git20150204.661c8bb2-0ubuntu0ricotz~trusty), multiarch-support:amd64 (2.19-0ubuntu6.5, 2.19-0ubuntu6.6), cups-core-drivers:amd64 (1.7.2-0ubuntu1.2, 1.7.2-0ubuntu1.5), cups-server-common:amd64 (1.7.2-0ubuntu1.2, 1.7.2-0ubuntu1.5), libopenvg1-mesa:amd64 (10.1.3-0ubuntu0.3, 10.4.0~git20141112.7a82961b-0ubuntu0ricotz~trusty), python-samba:amd64 (4.1.6+dfsg-1ubuntu2.14.04.5, 4.1.6+dfsg-1ubuntu2.14.04.7), e2fsprogs:amd64 (1.42.9-3ubuntu1, 1.42.9-3ubuntu1.2), libegl1-mesa-drivers:amd64 (10.1.3-0ubuntu0.3, 10.5.0~git20150204.661c8bb2-0ubuntu0ricotz~trusty), firefox-locale-en:amd64 (35.0.1+build1-0ubuntu0.14.04.1, 36.0+build2-0ubuntu0.14.04.4), xserver-xorg-video-sisusb:amd64 (0.9.6-2build1, 0.9.6+git20140806.293d0902-0ubuntu0sarvatt~trusty), nvidia-settings:amd64 (346.35-0ubuntu1~xedgers14.04.1, 346.47-0ubuntu1~xedgers14.04.1), libdrm-intel1:amd64 (2.4.56-1~ubuntu2, 2.4.59+git20150225.1f73578d-0ubuntu0ricotz~trusty), xserver-xorg-video-glamoregl:amd64 (0.6.0-0ubuntu4, 0.6.0+git20140801.347ef4f0-0ubuntu0sarvatt~trusty), libllvm3.4:amd64 (3.4-1ubuntu3, 3.4.2-3ubuntu2~xedgers), libgl1-mesa-dri:amd64 (10.1.3-0ubuntu0.3, 10.5.0~git20150204.661c8bb2-0ubuntu0ricotz~trusty), xserver-xorg-video-neomagic:amd64 (1.2.8-1build1, 1.2.8+git20140806.74a9a343-0ubuntu0sarvatt~trusty), libcups2:amd64 (1.7.2-0ubuntu1.2, 1.7.2-0ubuntu1.5), cups-daemon:amd64 (1.7.2-0ubuntu1.2, 1.7.2-0ubuntu1.5), libcomerr2:amd64 (1.42.9-3ubuntu1, 1.42.9-3ubuntu1.2), firefox:amd64 (35.0.1+build1-0ubuntu0.14.04.1, 36.0+build2-0ubuntu0.14.04.4), libdrm-radeon1:amd64 (2.4.56-1~ubuntu2, 2.4.59+git20150225.1f73578d-0ubuntu0ricotz~trusty), libfreetype6:amd64 (2.5.2-1ubuntu2.3, 2.5.2-1ubuntu2.4), libcupsmime1:amd64 (1.7.2-0ubuntu1.2, 1.7.2-0ubuntu1.5), cups-client:amd64 (1.7.2-0ubuntu1.2, 1.7.2-0ubuntu1.5), libwayland-server0:amd64 (1.4.0-1ubuntu1, 1.7.0-0ubuntu1~trusty1), libc-dev-bin:amd64 (2.19-0ubuntu6.5, 2.19-0ubuntu6.6), libcupsimage2:amd64 (1.7.2-0ubuntu1.2, 1.7.2-0ubuntu1.5), libc-bin:amd64 (2.19-0ubuntu6.5, 2.19-0ubuntu6.6), libc6:amd64 (2.19-0ubuntu6.5, 2.19-0ubuntu6.6), libss2:amd64 (1.42.9-3ubuntu1, 1.42.9-3ubuntu1.2), libglapi-mesa:amd64 (10.1.3-0ubuntu0.3, 10.5.0~git20150204.661c8bb2-0ubuntu0ricotz~trusty), cups:amd64 (1.7.2-0ubuntu1.2, 1.7.2-0ubuntu1.5), libwayland-cursor0:amd64 (1.4.0-1ubuntu1, 1.7.0-0ubuntu1~trusty1), samba-common-bin:amd64 (4.1.6+dfsg-1ubuntu2.14.04.5, 4.1.6+dfsg-1ubuntu2.14.04.7), libgl1-mesa-glx:amd64 (10.1.3-0ubuntu0.3, 10.5.0~git20150204.661c8bb2-0ubuntu0ricotz~trusty), libxatracker2:amd64 (10.1.3-0ubuntu0.3, 10.5.0~git20150204.661c8bb2-0ubuntu0ricotz~trusty), language-pack-gnome-en:amd64 (14.04+20141110, 14.04+20150219), cups-bsd:amd64 (1.7.2-0ubuntu1.2, 1.7.2-0ubuntu1.5), xserver-xorg-video-intel:amd64 (2.99.910-0ubuntu1.4, 2.99.917+git20150225.2b978c71-0ubuntu0sarvatt~trusty), samba-libs:amd64 (4.1.6+dfsg-1ubuntu2.14.04.5, 4.1.6+dfsg-1ubuntu2.14.04.7), xserver-xorg-video-ati:amd64 (7.3.0-1ubuntu3.1, 7.4.99+git20140806.fbf575cb-0ubuntu0sarvatt~trusty), libglamor0:amd64 (0.6.0-0ubuntu4, 0.6.0+git20140801.347ef4f0-0ubuntu0sarvatt~trusty), ca-certificates:amd64 (20130906ubuntu2, 20141019ubuntu0.14.04.1), libdrm-nouveau2:amd64 (2.4.56-1~ubuntu2, 2.4.59+git20150225.1f73578d-0ubuntu0ricotz~trusty), libcupscgi1:amd64 (1.7.2-0ubuntu1.2, 1.7.2-0ubuntu1.5), libwayland-egl1-mesa:amd64 (10.1.3-0ubuntu0.3, 10.5.0~git20150204.661c8bb2-0ubuntu0ricotz~trusty), libwayland-client0:amd64 (1.4.0-1ubuntu1, 1.7.0-0ubuntu1~trusty1), xserver-xorg-video-trident:amd64 (1.3.6-0ubuntu5, 1.3.6+git20140806.562c38ca-0ubuntu0sarvatt~trusty), smbclient:amd64 (4.1.6+dfsg-1ubuntu2.14.04.5, 4.1.6+dfsg-1ubuntu2.14.04.7), libgbm1:amd64 (10.1.3-0ubuntu0.3, 10.5.0~git20150204.661c8bb2-0ubuntu0ricotz~trusty), libcupsppdc1:amd64 (1.7.2-0ubuntu1.2, 1.7.2-0ubuntu1.5), libc6-i386:amd64 (2.19-0ubuntu6.5, 2.19-0ubuntu6.6), cups-common:amd64 (1.7.2-0ubuntu1.2, 1.7.2-0ubuntu1.5), xserver-xorg-video-radeon:amd64 (7.3.0-1ubuntu3.1, 7.4.99+git20140806.fbf575cb-0ubuntu0sarvatt~trusty), language-pack-en-base:amd64 (14.04+20140707, 14.04+20150219), language-pack-gnome-en-base:amd64 (14.04+20140707, 14.04+20150219), libwbclient0:amd64 (4.1.6+dfsg-1ubuntu2.14.04.5, 4.1.6+dfsg-1ubuntu2.14.04.7), cups-ppdc:amd64 (1.7.2-0ubuntu1.2, 1.7.2-0ubuntu1.5), libc6-dbg:amd64 (2.19-0ubuntu6.5, 2.19-0ubuntu6.6), linux-libc-dev:amd64 (3.13.0-45.74, 3.13.0-46.76), samba-common:amd64 (4.1.6+dfsg-1ubuntu2.14.04.5, 4.1.6+dfsg-1ubuntu2.14.04.7), libdrm2:amd64 (2.4.56-1~ubuntu2, 2.4.59+git20150225.1f73578d-0ubuntu0ricotz~trusty), language-pack-en:amd64 (14.04+20141110, 14.04+20150219), unattended-upgrades:amd64 (0.82.1ubuntu2, 0.82.1ubuntu2.1), libc6-dev:amd64 (2.19-0ubuntu6.5, 2.19-0ubuntu6.6), libsmbclient:amd64 (4.1.6+dfsg-1ubuntu2.14.04.5, 4.1.6+dfsg-1ubuntu2.14.04.7), xserver-xorg-video-nouveau:amd64 (1.0.10-1ubuntu2, 1.0.11+git20141030.3fb97d78-0ubuntu0sarvatt~trusty2)
End-Date: 2015-03-01 17:23:55
Alguma ideia de qual pode ser o problema?
Eu encontrei o mesmo problema. Consertei com isso executando:
sudo apt-get update
sudo apt-get upgrade
a atualização fez o trabalho real. também verifique isso se você se preocupar com a execução de "upgrade" O que é a diferença entre o apt-get update e upgrade?