Circuit check for noob

hello,
i’m experimenting too with GP2Y1010AU0F, but i’ve found a strange behaviour.
my sensor is conncted like datasheet explain, pin 3 direct to atmega (i’ve also try using a mosfet but it do not change)
if i run GP2Y1010AU0F with 5.330 voltage i read an output voltage between 0.800 and 0.850
if i run GP2Y1010AU0F with 5.080 voltage i read an output voltage between 0.770 and 0.830
if i run GP2Y1010AU0F with 4.670 voltage i read an output voltage between 0.700 to 0.770
so there’s a small drift when supply voltage change.
i suppose the fig 3 of datasheet, from which we can extract slope and offset to find dust sensity, it’s 5.0v supply voltage, so reading an “incorrect” voltage would bring to incorrect mg/m^3 conversion.
have you also find this behevior?
have you find a way to balance the supply voltage drift?

thanks all