Yes, that's it! Thanks for the correction Just17.
I'm at work ATM and not in KDE so I was using my -always- failing memory 
But I think you can set it also for internal devices and not only for attached devices...
Device Notifier will only popup when you connect an external device... Or am I wrong? 
Attached Devices are the internal ones ......... which are permanently attached (EDIT) ....... and also the removable devices which are plugged in.
Disconnected Devices lists devices that have been attached in the past and are no longer attached.
You can bring up Device Notifier at any time you wish by clicking on its icon in the tray.
You have the option of editing the settings there also.
You can also put Device Notifier as a widget on the Desktop and have it display all partitions/devices in your system.
