I don't think this is much related to unity, since I experienced this also in older versions of ubuntu (this problem has always been there ihmo).
When the window is minimized, sometimes doesn't get mapped again, and this is not possible also using other window managers (or tool such as libwnck). ** Changed in: unity Status: Confirmed => Incomplete ** Changed in: unity (Ubuntu) Status: Confirmed => Incomplete ** Also affects: update-notifier (Ubuntu) Importance: Undecided Status: New ** No longer affects: unity ** Changed in: unity (Ubuntu) Status: Incomplete => Opinion ** Changed in: unity (Ubuntu) Status: Opinion => Invalid ** Also affects: compiz Importance: Undecided Status: New ** Also affects: compiz (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of DX Packages, which is subscribed to unity in Ubuntu. Matching subscriptions: dx-packages https://bugs.launchpad.net/bugs/1389573 Title: Update-notifier window invisible in utopic Status in Compiz: New Status in “compiz” package in Ubuntu: New Status in “unity” package in Ubuntu: Invalid Status in “update-notifier” package in Ubuntu: New Bug description: Somehow I ended up with update-notifier not being visible on my utopic laptop. I can see it in the dock on the left, and I can interact with it that way (right-clicking to choose "install available software"), and I can even close it out from there. But I cannot cause its main window to appear on any desktop. Rebooting does not clear this problem, and it happens even with the reboot notifications. ProblemType: Bug DistroRelease: Ubuntu 14.10 Package: update-notifier 3.157 ProcVersionSignature: Ubuntu 3.16.0-24.32-generic 3.16.4 Uname: Linux 3.16.0-24-generic x86_64 ApportVersion: 2.14.7-0ubuntu8 Architecture: amd64 CurrentDesktop: Unity Date: Wed Nov 5 08:48:20 2014 InstallationDate: Installed on 2014-05-29 (159 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417) SourcePackage: update-notifier UpgradeStatus: Upgraded to utopic on 2014-10-24 (11 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/compiz/+bug/1389573/+subscriptions -- Mailing list: https://launchpad.net/~dx-packages Post to : dx-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~dx-packages More help : https://help.launchpad.net/ListHelp