UPDATE: Autodesk is aware of this issue and can reproduce the problem CaseNo:10466148, This only happens when you ahve your properties palette open.

This is a difficult one to explain. So I have made a screencast to show you here

But basically when selecting something that is a civil 3d object with a “Left-Right” or “right-left” selection and you drag your mouse outside the autocad window (say the start menu). Autocad no longer is the current program. Requiring the user to select the autocad icon on start menu. Or click on the top bar to regain focus..

Very frustrating as my commands often have to be done twice as a result. OR more often then not a complicated selection during a command that may have taken a little while is lost.

Additionally once this has occurred once. A left-right selection on the object without even dragging outside will continue to allow the program to lose focus!

See example file and explanation below so you can recreate problem for yourselves.