You need at least one extra light, either a spot or an infinite, since IBL/HDRI lights don't do shadows on their own. That's my two cents worth at the moment. (whistling and waiting for Acadia the link goddess to make an appearance)

"A lonely climber walks a tightrope to where dreams are born and never die!" - Billy Thorpe, song: Edge of Madness, album: East of Eden's Gate

Weapons of choice:

Poser Pro 2012, SR2, Paintshop Pro 8