onmouseover and selection and images

How would I cause the onmouseover event to give the appearance of selecting the entire row, like clicking on a row does? Right now, the regular mouseover event highlighting doesn't highlight the last column (the one that appears when the grid is wider than its defined columns), and it behaves oddly when images are present in the row (also unlike the row selection function). I would be happy with a solution that just triggers a row selection when onmouseover occurs, as I have no use for row selection.

Also, how would I get better control of the image placement in the cells? Right now, if I try to adjust an image's position by using a style attribute with "position:relative; top: 2px;" it makes the row height taller and displaces the column dividers.