Following installation of DraftSight Pro the system continually freezes with the message Not Responding. This happens when opening the program and during use. The software eventually resolves the issue but only after a long wait and then freezes again after a few commands.

I have tried uninstalling and reinstalling the software, cleaning the registry and updating video cards etc all to no avail. 

My computer and memory should be quite adequate as it easily and efficiently runs Autodesk Revit.

Any suggestions as to what might be causing this issue would be much appreciated.