Since I upgraded to KDE 4.10, the taskbar does not always properly clear the alert state of windows anymore. Often I end up with windows that demanded attention at some point, but still appear highlighted even though I clicked them long ago. I have to close the windows to get rid of this highlighting.

Reproducible: Sometimes

Steps to Reproduce:
I cannot reproduce this.
Actual Results:  
Sometimes, when a window flashes in the taskbar, if I click it, it keeps the highlighted state. I noticed this with Kopete, Konsole, Firefox and Thunderbird windows.

Expected Results:  
The state should be cleared once I activate the window.

This did not happen with KDE 4.9.

Using xprop, I had a look at the _NET_WM_STATE of such windows: It is empty.