I just discover another problem with icon widget .

1. from menu select terminal program
2. right click and select add to desktop . it will add terminal icon widget on desktop .
3. right click on the terminal icon widget and select icon setting
4. click application tab
5. advanced options
6. tick run as different user
7. click ok

once finish you will notice that the icon change to question mark . and when you run it , it will prompt error "KDEInit could not launch /usr/lib/kde4/libexec/kdesu"

by the way if you check on the menu , you will notice that terminal is missing .