damn you ie

Obviously do one who reads this uses Internet Explorer or they would have mentioned (hopefully) that my little drop case trick doesn't work in IE. This is the CSS I'm currently using:

p.dc:first-letter {
  float: left;
  font-size: 2.5em;
  text-transform: uppercase;
  font-weight: bold;
  font-family: Georgia, Times, Verdana;
  line-height: 0em;
  color: #707070;
}

It looks as though IE7 does support the :first-letter pseudo class, but the box model is failing with the float: left. Any suggestions?