If, indeed, the hardware is properly calibrated, take a look at the Poser version you are using.  PoserPro corrects for gamma upon render, something that is lacking in previous versions.  Poser 7 and earlier must be corrected either in postwork or through procedural shader nodes if a material room exists.  Bagginsbill has been adamant about disseminating point for quite some time.  And I believe there will be a rude-awakening for many artist converting to Poser 8 when they find that previous renders are truly over lit and completely off balance.