This is "Bug 278891 - a program closed after dragging to another desktop creates empty space on taskbar" on kde available at https://bugs.kde.org/show_bug.cgi?id=278891.
As you can see the bug has been closed as invalid together with its tons of duplicates as Aaron judged the signal to noise ratio on the tracker to be too deteriorated. Apparently kde is growing this attitude of punishing those who post useless comments on the tracker by leaving unfixed those bugs that annoy them most. ** Changed in: kde-workspace (Ubuntu) Status: Incomplete => Confirmed ** Bug watch added: KDE Bug Tracking System #278891 http://bugs.kde.org/show_bug.cgi?id=278891 ** Also affects: kdebase-workspace via http://bugs.kde.org/show_bug.cgi?id=278891 Importance: Unknown Status: Unknown -- You received this bug notification because you are a member of Kubuntu Bugs, which is subscribed to kde-workspace in Ubuntu. https://bugs.launchpad.net/bugs/855572 Title: KDE Taskbar has blank space between items To manage notifications about this bug go to: https://bugs.launchpad.net/kdebase-workspace/+bug/855572/+subscriptions -- kubuntu-bugs mailing list kubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/kubuntu-bugs