Kubuntu 13.10 - Wireless password can't be set if alrlready connected via ethernet cable

[Oliver]

On a fresh install of Kubuntu 13.10 it is not possible to complete the password entry for a wireless network connection in KDE if the computer is already connected via an wired Ethernet cable connection.
The buttons to complete the entry for the password is missing and hitting the return button on the keyboard has no effect.

But luckily there is a workaround.
Unplug the Ethernet cable from your computer.
After that it is possible to enter the password for the wireless network connection and complete the entry.
The button to complete the entry does also show up this time.
After you are finished you can again plug your Ethernet cable into your computer to use both connection types, wireless and none wireless.