When chasing/researching a problem with AutoCAD, you want to rule everything else out to make sure it is AutoCAD especially with all the customization methods and file types that can cloud the real source of the issue.

     You accomplish this state of AutoCAD being "naked" by making sure that you have no network connected if possible even the client, no profiles, no customization, no 3rd party AutoCAD applications, clean drawing file from scratch with no blocks or Xrefs, and nothing else running on the desktop not even the seemingly harmless MP3 player or browser. Also reset to a default OOTB "Out of the Box" profile. Now with most of the smoke out of the way you can see if the problem still occurs from scratch steps and the possible solution.

-Shaan