i had this! i think... i updated and this problem started so it sounds the same... not sure about the numbers
goto your advanced settings... and your graphics car tab... colour correction - select the overlay. change the drop down tab at the bottom to advanced and make the gama go up in a diagonal line... not a curve
worked for me
heres my thread about the problem
http://shoutbox.menthix.net/showthread.php?tid=47121