Setting the screen grid size

[John Desmond]

Salutations, gentlefolk,

In Kubuntu Linux 8.04.1, kernel 2.6.24-14, KDE 3.5.10:

After left-clicking on the Desktop, getting the 'Configure -
KDesktop' menu, and clicking the  'File Icons' tab:

How do you adjust the 'screen grid',
  so that if you have set the icon size to '22'
   (under 'System settings / Appearance / Icons / Advanced'),
and you click 'Automatically line up icons',
  it will distribute them evenly,
  not mash them together in clumps with wide gaps between ?

Yours,John Desmond