Just building my first page with the yahoo yui grids css layouts. First impressions are that it's going to be a God-send tool. The one issue I've had so far is that when I set a background-image, it didn't fill the browser screen just the area occupied by my header, content & footer div tags.

Solution is simple, just set the body element to 100% height. In order to make cross-browser development coding as smple as possible, yui applies a 'reset' css set of styles that effectively clears-out any defaults a browser may have against certain elements and that includes body height.