I found that the grouping tool had caused a new material region to get interspersed between an existing region. There are two 'g' lines- the first one names the mtl for the group and the second one is empty, but it has beneath it the coordinates for the group. This may be UV data only- not sure about that yet. Also not sure if the name of the group shouldn't be on the empty 'g' line; just like the mtl name is on the same line as the g above. If the material group should be named there and it is not, that could explain how only certain areas are affected. It would be those areas between the interspersed new material that are not named so that Poser doesn't know where to find them. Just a theory though. =};-}>