help exporting to Unreal

Hello.

I have an .obj I imported that was made in XSI that I want to export to Unreal Ed. I have SM-Export v1.1.

-The model has a total of 6 seperate pieces with 3 materials assigned to it. When I select all of the parts the exporter only shows the info for one of them, like I only have that one selected. Do I need to combine them all before I export it or will it only export the one that it’s showing the info for?

-For each part I select it’s saying there are X number of lost verts. What does that mean and how can I fix it?

-How can I check to see if the material info didn’t get lost?

-It also says invalid next to textures.

Any help would be very much appreciated.