Gnome 2.4 Icon Grid

I like the icon grid in Gnome 2.4 but I would like to adjust it. When placing the icons on the desktop at the leftmost or rightmost grid position, part of the icon is hidden by the display edges, making them a little more difficult to see. What I would like to do is to "shift" the icon grid half a grid space horizontally. I've looked in the help manual (no help), explored Gnome 1 Control Center, and did a Google search, all to no avail. Does anyone know how to adjust the grid? Any pointers to more info will be appreciated. Don Henson