OBO John Barney

V1R3 installs on Ubuntu 12.04 but when I open dwg files created in AutoCad, there are heavy lines criss-crossing the drawing area.  How can this be fixed?  When creating a drawing in V1R3, the drawing area is clean (no extraneous lines) and those drawings they re-open normally.  Must have something to do with AutoCad compatibility.  My AutoCad dwgs were created in Windows XP.  Thx,  JB