I fixed this problem by renaming the file and re-linking it. But why did this happen in the first place? The texture was properly linked and even showed in preview window. any ideas?

Is there a value to your link?  For example, image map connected to Diffuse_color but Diffuse_value set to zero.

Sorry for the late reply. The diffuse had a value setting. when I relink another image just to check, then it rendered that particular image. but when I selected the original texture again, it just rendered white. Then I renamed the Original texture, re-linked it then in rendered fine. Its almost like poser was to lazy to read the file.

That is strange.  Anything unusual about the original name that Poser didn't like?

I've had this happen.  When it does, it turns out that Poser has renamed the texture node to Color Texture instead of Image Map.  Delete it, load a new Image Map node and assign the image to that and everything works then.

I don't know why Poser does this, but it happens very seldom.  Next time this happens go to the material room and see if the name of the node has changed to Color Texture.  Maybe someone knows a fix for this.

John