Sometimes my taskbars (I have one per screen) end up having an empty entry as the first entry. For a double row taskbar it means the topmost-leftmost taskbar cell is empty. For a singlerow taskbar see the attached screenshot. I'm not sure how to trigger it, and after a while (starting/closing application) the taskbar fixes itself. Reproducible: Sometimes
Created attachment 75729 [details] Taskbar bug
Still there in master
*** Bug 276226 has been marked as a duplicate of this bug. ***
Thank you for your report. The taskbar applet has been completely rewritten for KDE Workspaces 4.11 I am unable to reproduce this with the new version. Please reopen this bug if you encounter this in 4.11 onwards.
*** Bug 281803 has been marked as a duplicate of this bug. ***