Hi Tania, there is a setting in the moi.ini file that you can edit to turn off writing off UV coordinates to OBJ format. I do not currently have a setting for LWO format for that but I will add one in for the next v3 beta.

The setting for OBJ format can be found by going to Options > General, and push the "Edit .ini file" button, and then in that text file find the section [OBJ Export] and set:

[OBJ Export]
WriteTextureCoordinates=n

- Michael