Hi, i found some threads talking about the same vsync problem:
http://forums.autodesk.com/t5/autocad-for-mac-general/mac-autocad-2013-student-version-flickering-wh...

http://forums.autodesk.com/t5/autocad-for-mac-general/enable-vertical-sync-v-sync-in-autocad-2014-fo...

http://forums.macrumors.com/showthread.php?t=1603811

It seems that we finally found the cause. So is there a way to adjust, enable or change this vsync parameter?

Andrea.