I know some people have had problems with getting the bump/normal mapping and color textures from ZBrush into Houdini. I wrote an informal tutorial on how to do this in my last post. Just scroll to the bottom of the page and have a look at how to go about this. Sorry I am too lazy to repost this again here so I am just going to make a link to it.
http://odforce.net/forum/index.php?showtopic=3775&st=12 [odforce.net]
Here is an example image that I made from a model in ZBrush and then applied the normal map to the color channel to show that their are not seam problems and to the normal displacement channels.
Cheers,
Nate Nesler