Version: (using KDE KDE 3.97.0)
Installed from: Mandriva RPMs
The problem is that plasmoids in the pannel don't have those three buttons (configure, resize, close) and can only be closed with right-click menu which not all plasmoids have.
I suggest to add those three buttons to pannel plasmoids on middle-click or on hover, though I think middle-click would be better (best if configurable).
*** This bug has been marked as a duplicate of 154119 ***