In your render settings, make sure you have unchecked "Cast Shadows".  That's what you're seeing, the shadows from one or more of the lights.

Attached Link: http://www.runtimedna.com

If you go to RDNA and look in their free stuff area under "Poser Lights", you can get lots of free light sets that work really well in Poser 5.

And seeing that this is your first post in the Poser forum, I am going to assume you are brand spanking new and provide you with a link to my "mini essay" for new poser users.  Hopefully the information will be of some help to you :)

http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2678510&page=1#message_2864456

that's the tell-tale default poser look that 3D snobs laff at - no shadows. I think Acadia compiled a series of links in a recent thread here - keyword "Lighting". it's not an easy subject to learn, unfortunately.

Attached Link: http://market.renderosity.com/mod/forumpro/showthread.php?thread_id=2662390

Poser is a complicated program with a steep learning curve and taking on too much to learn at one time can be daunting and lead to feelings of failure and defeat.  I think as a new user that your efforts are better spent elsewhere when you first start because there are really great free lights around that you can rely on until you get to the point of feeling comfortable enough with the basics.

Just a note.  Poser 5 and Poser 6 handle lights differently.  So when you look through the links stick with ones for Poser 5 because the Poser 6 ones won't be of use to you because there are some lights and  lighting features  that Poser 5 doesn't have.

Anyway, it's my advice to stick with "premade" lights and poses until you get comfortable working in Poser and can render decent images.  Then branch out and pick up something else to learn like altering the pose to your own style, or trying to create your own lights

Creating lights in any poser program is complicated, but it's more complicated in some versions that others.  With Poser 5 your need quite a few lights to produce good lighting. Some premade light sets have 20 lights!!!! 

Poser 6 on the other hand is much more friendly when it comes to creating your own lights because you only need to create between 1 and 5 lights to get decent lighting.  However, because of the way it handles lights and the types of lights it uses and some of the lighting features, it has it's own set of complications to learning.

Anyway, check out that RDNA link and download the free lights there. They are wonderful and work very well in Poser 5 and will make your poser life so much more easy to start :)