I\'m currently having problems with Internet Explorer 8 ignoring padding/line-heights that I have on a list which includes a check box.
To start off here is my CSS and X
It seems that in IE (and Opera as it happens) the checkbox doesn't participate in the inline content of the li, so, since the label doesn't either because it's floated, the line-height setting for the li has no effect.
Add a after the label in the checkbox line, and that will be sufficient for the line-height to take effect, and all the li s will be the same height.