I've never used LT, but I do have something you might consider. I am using ADT4. I'm the only one in an office of 9 drafters. I have to save drawings back to 2000 format. If there are ADT elements within the drawing their proxy objects are uneditable and 2D. Also, in any case some computers get about 50 alert boxes each time they open a drawing that I've saved. You might see if Kate can open one of your drawings as she uses LT.