Quote - I've sent the test scene, but I've got an interesting new result. 

Apparently the texture crosstalk is only occurring if I select the option to allow re-posing inside Vue when I import the Poser scene.  I have been leaving that option selected the whole time and didn't think to try to disable it until now.  I don't see anything in the SkinVue user guide indicating that this option should not be selected, so I'm assuming that this is not normal.  But it's definite progress.  If I uncheck the reposing option, the SkinVue modifier works just fine on both characters in the same scene.  I've revalidated this with 4 separate scenes now with the same results each time.

allow re-posing = texture crosstalk
disallow re-posing = all's well

Well that covers it then.  I never have used the re-poser in Vue - way too slow versus just using Poser and re-importing.  I understand now why SkinVue can't distinguish mulitple characters with the re-poser turned on.  It's because the materials in Vue are virtual when using the re-poser and are not tied to a given object physically as they are when importing without the re-poser turned on.  I'll check into this further, but I don't think there is a workaround for this since there is no physical tie between Vue Material objects and Poser when using the re-poser.