alt+tab to get Konsole in focus does not allow typing into it

[H.S.]

Hello,

In Hardy, fully updated, using KDE, I am having this problem that while
switching window focus to Konsole using ALT+TAB, I cannot type in
Konsole's window. The usual case is to shift focus from Emacs or from
Firefox to Konsole. The konsole window does come in front and it appears
to get the focus, but I cannot type anything inside that windows.

However, if I shift focus by clicking the mouse on Konsole, then
everything works fine in the Konsole windows.

Any idea what could be going wrong?

thanks.