By default, checkboxes have some margin and perhaps padding so they take up a bit more space than is needed. I needed to make some checkboxes take up the least amount of space possible, and the following css:
didnt work in IE6 and IE7, while working perfectly in firefox (as usual).
Add the following IE only css:
This fixes the problem on IE6, and IE7, i dont know if IE8 has this problem or not.