click to KDE-Start-Symbol (left button) 
click to an cascade-element ( Office as example ) of pop-up-menu (right button)   
   select  "Add to Panel"  ( using left button) 

An new element is now in the panel ( the icon-picture is the same, as in the pop-up-menu)

click on the new element in the penal  -> a pop-up-menu raised 
  however, the elements are not the entries of selected  cascade-element 
               
If an single-element selected   (not a cascade-element), then this element will be placed in the panel.


Reproducible: Always

Steps to Reproduce:
1.see Details
2.
3.

Actual Results:  
see Details

Expected Results:  
Add the selected entry only to the panel resp. to the desktop