Version: (using KDE 4.2.96) OS: Linux Installed from: Unlisted Binary Package The "soliddevice" DataEngine shows the free space of a device if it is mounted; if it isn't the DataEngine doesn't provide the "Free Space" key. But if you start the DataEngine when a device is umounted, and then you mount it, the "Free Space" doesn't show up, while, e.g., the "Accessible" key changes its value to true. Then if you set an update interval, after the timeout, the "Free Space" key will show up and you'll be able to access to it. You can see all of this using the plasmaengineexplorer.
Resolved according to revision: 1013933