I have two desktop systems running Mageia 2 with kde 4.8.4 running just as I want it.
I have just installed it on my wife's HP laptop where it also runs beautifully except
that when an application is launched, nothing appears on the panel. I have had this
previously elsewhere but always managed to overcome it but not on this occasion.

I have even recreated the panel from scratch but that did not help. Is there a
'correct' way of going about this?

TIA

try adding the task manager widget to the panel

You may need to make sure widgets are unlocked before attempting to add a widget.