glBlendColor(..) working incorrectly

noticed something when i updated my drivers from 8x.xx to 91.31 on my gffx

glBlendColor( x,x,x,1 );
setting x to higher than 1 results in what looks like modulation eg glBlendColor( 2.5 ) acts like glBlendColor( 0.5 );
in previous drivers 2.5 acts like 1.0

from the gl spec

Blend Color
The constant color Cc to be used in blending is specified with the command
void BlendColor( clampf red, clampf green, clampf blue,
clampf alpha );
The four parameters are clamped to the range [0, 1] before being stored. The
constant color can be used in both the source and destination blending functions