Some unknown property is giving the <h4> attribute headings huge top and bottom margins (I say unknown because Firebug doesn't show any margin setting affecting them at all).
If you explicitly set small margins for them, all is well:
Code:
label, h4.optionName {
line-height: 1.5em;
padding: 0em;
float: left;
margin: 0.1em;
}
These headings are both h4.optionName and label, so the font sizing properties apply twice, making the line-height extra large. Shrinking that doesn't help much, because the margins are still there.