The battery widget does not display the correct remaining percentage

The battery widget does not display the correct remaining percentage even if acpi -b shows correct information.
Simplest way to reproduce the problem is to unplug the charger: the KDE widget will keep showing 100% while acpi -b shows correct information.

More details:
https://www.dropbox.com/s/8qy06i61olih3la/OpenSUSE%2064-bit-2014-07-07-23-03-25.png



Thanks for the help,

Radu