Display: Table-cell doesn't center the div

[a7xdm]

I am trying to center an image within a div and I used the display:table & display: table-cell method. It is centered but it is off by a few pixels from the top. What can I do to correct this?\[code\]CSShtml, body { width: 100%; height: 100%;}body,html { margin: 0; padding: 0; color:#ffffff; text-align: center;}#wrapper{text-align: left;width: 940px;margin: 0 auto;margin-top: 22px;background-color: #ffffff;overflow: hidden;}header {width: 908px;height: 76px;display: table;border-style:solid;border-top-width: 16px;border-bottom-width: 16px;border-top-color: #ffffff;background-color: #cccccc;}#headerdiv { display: table-cell; vertical-align: middle; margin: 0; height: 28px; }HTML<div id="wrapper"><header><div id="headerdiv"><img src="http://stackoverflow.com/questions/15842535/logotest.gif" height="28" width="180" alt="test"></div></header></div>\[/code\]