When I log into KDE on any driver above 304.64 the brightness is two values below the brightest, when I try to adjust the brightness with my FN - Brightness UP key combo it flashes up to the brightest setting for a second then back down to the two values below it. I have tried multiple driver versions above 304.64 and all of them have the same problem. Following are install details, if further information is needed I will post it.
Dist: Debian Testing 7.0
Computer: Toshiba Qosimo (Laptop)
Nvidia version that works: 295.71 and 304.64
Nvidia versions that do not: 310.32, 310.40, 313.09 beta and 313.18 beta