This may be one for this specialized forum (where you may be able find the answer from previous threads),
or for Customer Care (tick I Still Need Help and hope for an agent available for a chat),
or for Adobe Support (phone),
Do you have any third party plug-ins? If so, try removing them and see if that helps. Then you can add the plug-ins back one by one to see which one is causing the issue.
Additionally, if you have any third party devices like Wacom, also try remove/uninstall them.
Lastly, can you try manually remove the preferences file for Illustrator: http://adobe.ly/Ty949V
Let us know how it goes.