Interface color of Illustrator CS6 keeps changing back to black???

Hi does anyone have any advice. I am a long time user of Illustrator yet can't figure out why when I set the interface color of Illustrator CS6 to the lightest color palette it never sticks.
Every time I restart Illustrator CS6 the interface color keeps changing back to black. Thank you in advance.

Try starting illustrator as an administrator. Set the interface color and exit. Restart to see if it sticks. Failing that working, you may need to delete your preferences. And if that doesn't work, it may be your computer's user profile. To test that, create a new user and run illustrator and see if in that new user profile it sticks.

Mike