This is a solution I've used before to accomplish vertical centering in CSS. This works in all the modern browsers.
http://www.jakpsatweb.cz/css/css-vertical-center-solution.html
Excerpt:
<div style="display: table; height: 400px; position: relative; overflow: hidden;">
<div style="position: absolute; top: 50%;display: table-cell; vertical-align: middle;">
<div style="position: relative; top: -50%">
any text<br>
any height<br>
any content, for example generated from DB<br>
everything is vertically centered
</div>
</div>
</div>
(Inline styles for demonstration purposes)