are you talking about desktop labels (number of desktops available), or your list of open application windows.
If the list of windows then, I have them ungrouped but cant find the option anywhere. Im sure there is a box to tick/untick in taskbar options but ,as Isay, Icant find one. Ive been using this Mint 9 KDE for about 18 mths.
I wonder if it deprnds on the theme being used
I was looking around in settings/system settings..appearance and desktop