Owing to how the CSS Box Model works, borders tend to mess things up quite a bit in FluidGrid Layouts. My Advice is to add the following code to any LayoutDivs you want borders applied to:
#LayoutDivName {
box-sizing: border-box;
-moz-box-sizing: border-box;
-webkit-box-sizing: border-box;
border: 1px dotted #666; /**adjust as suit**/
}
Below is a demo with borders applied to all Divs inside the parent .gridContainer
http://alt-web.com/FluidGrid/Fluid2.html
Nancy O.