Couple of things. Because this is a grouped mesh, the model has a material list, that material list needs to correspond with the correct textures, so converting a model from one format to the next will not necessarily keep that material list and in turn, cause model corruption.
Models also needs to be centered in a model editor, and you also need to confirm the model is the correct size, there should be no reason for the model not to show up even with texture corruption the model should show up black.
It's very likely that the size isn't correct, I suggest importing the model in your favorite model editor and importing an AI character to confirm that the model is the correct size.
Win7 pro, Intel 2500K @3.7ghz 660GTX 8gig ram 16tb HDD