[Swlug] Kubuntu 14.04, 64 bit and the taskbar?

[stephen]

Dear All

In Windows the strip at the bottom of the screen is called a taskbar. 
And like Windows, my Kubuntu has a group of icons on the left and right 
of the taskbar..

It is the bit in the middle I have mucked up. When I start an 
application an icon to that instance appears in the middle section.

But not any more. I have done something and I do not know what, but now 
no icon appears.

I like this feature and would like to reinstate it

Any help appreciated

Stephen
Swansea, but currently in London