I am a new SU user. I am importing 3d dwg files that were originally created in AutoDesk Inventor and saved as dwg files. A few import nicely, but most do not. Either my computer does not respond at all or SU seems to be processing the image and then nothing shows up. My computer is a little older, but it still meets the minimum requirements for SU. Earlier, SU would crash when I tried to save an imported dwg file to skp. I updated the graphics card driver (ATI Mobility FireGL T2 128 MB) and the crashes stopped. I have a IBM ThinkPad T41p laptop with a 1.7 Centrino and 2GB RAM.