Poser simply does not import LightWave objects with UV maps. If it manages to import the object at all without weird errors, such as a lack of smoothing between unwelded vertices (the object's fault, not Poser's), it still can't read LW UV maps.
Poser is designed for OBJ and one UV map. A LWO might have a different UV map for each surface.
But even if you export a LWO with one layer, and one UV map for all surfaces, the UV's get lost when Poser opens it. Don't know why, but it could be because Poser is still using the earlier LWO format, before LWO2, which introduced UV maps and came out with LightWave 6.0 or 6.5.

I might add the inverse is true, too - if you export a Poser figure from Poser, even one fully UV mapped, as LWO, the UV map vanishes somewhere.

EDIT:
I missed this:

Quote -
they show up only as solid dark colors on the surfaces to which they are applied.

That could be because the object might have double-sided polygons, which Poser also can't handle.