Version: (using KDE Devel) I opened Konsole and maximised it. I opened Iceweasel (Firefox) and maximised it. Then I clicked on the task bar entry of Iceweasel to minimise it. I clicked again... and again... and again => Icewaesel minimised and maximised but suddenly the popup shew up for Konsole although the mouse still hovered the Iceweasel entry. It jumbs to the other app here every 3rd to 10th click. BTW: Does the popup have to reappear after the click anyway? BTW2: It disturbes (by covering) the percentage popup shown by the file transfer dialog.
*** This bug has been marked as a duplicate of 154719 ***