30" Cinema Display, Brightness Icon Stays on, won't adjust

Okay I have an odd issue, my 30" Cinema Display brightness started acting up recently.

The Icon stays on or will flash on and off but the display will no longer adjust ? Not on the display or by keyboard. Nothing seems to help.

It will try to brighten, but then goes complete dim and stays dim to the point the keys will no control the brightness? Then I get the Icon constantly flashing on and off.

Is there a fix for this ?

Running 10.8.2 with my Mac Pro tower ... nothing has changed as far as I can tell, same set up I have been running for years ?

Anyone heard of this and is there a fix ?