As Chris says. Poser scales the texture down considerably for preview use. As part of the (necessarily for slow old computers) quick-and-dirty scaling down process, the pixels near the edge of the seams get logically OR'd with pixels outside the seams. Ways to lessen the effect are to use smaller textures sizes - if small enough no scaling down is required, and thus not pixel creep occurs (e.g. standard Poser 4 charater textures). 'Course rendered quality will be down. Extend image a little beyond borders, for the ideal it should be from the edge of the corresponding seam! But you can mitigate the effect by simply flooding the unused part of the UV Map with a color very close to that used on near the offending seams - or that of the one that bothers you most. Should be able to achieve this, perhaps even with blending, in Photoshop, with some careful masking steps.