cuando necesito colocar el pie de pagina hasta abajo cuando no hay suficiente contenido y que baje aun mas cuando el contenido supere el tamaño de pantalla, suelo utilizar esta técnica... revisa el código, pruebalo y adaptalo a tus necesidades.
Código CSS:
Ver original*{margin:0;padding:0;}/* reset rapido - no recomendado para un sitio en vivo */
p{margin-bottom:10px;}/* reset rapido */
html,body{margin:0;padding:0;height:100%;font:13px/1.5 arial,verdana,tahoma;}
#site{min-height:100%;}
#content{width:900px;margin:auto;padding-bottom:33px;}
#footer{background:#000;height:33px;margin-top:-33px;font:italic 700 11px/33px tahoma,arial,verdana;color:#fff;text-align:center;text-transform:uppercase;}
Código HTML:
Ver original<p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
</p><p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
<br /><br />hola mundo
</p> <div id="footer">pie de pagina
</div>
Nota: no olvides declarar un doctype valido