Select option not displaying in Internet explorer

Select option not displaying in Internet explorer

The following select options display fine in Firefox/Chrome but not in
IE8. Please help.
<select id = "vehicle" name = "vehicle" class = "vehicleSelect">
<option value = "-1" selected>&nbsp;</option>
<option value = "15">Car</option>
<option value = "16">Bike</option>
<option value = "17">Train</option>
</select>
CSS:
.vehicleSelect
{
width: 100%;
height: 100%;
font: 10px/1.45em "Lucida Grande",Verdana,Arial,Helvetica,sans-serif;
padding: 3;
border: 0;
}