Why does N.I.S. think Autodesk Alias Design 2012 downloaded directly from Autodesk have Malware?

I am using Autodesk for Students to try out some software for college. I have downloaded Sketchbook pro 2010 and 2011, AutoCad 2011 and 2012, and 3D Studio Max 2011 with no issues. Whenever I try and download Autodesk Alias Design 2012 Norton Insight immediately thinks it has malware and deletes it but gives no reason. I have tried contacting Autodesk but they can’t seem to help without more info. If I could tell them exactly why N.I.S. doesn’t like the download it might help them.