64 bit Fractal Extreme changes palette mapping ever so slightly

[panzerboy]

I upgraded recently to win7 64bit and got an immediate 2x speed increase in rendering in Fractal Extreme. Woohoo!
I thought I might revisit an older zoom movie and re-render it in a higher resultion, it was the first zoom I made at mere 384x240 resution.
But the colours have changed in the middle of the zoom, the start and end look sthe same but the palette if shifted ever so slightly.
I re-installed the 32 bit version and the same effect happened so I'm thinking it must be some standard math routines in Windows
now use higher precision perhaps?


On the left is a frame from my previously rendered zoom movie in Fractal Extreme 32 bit.
On the right is the shifted palette in fractal extreme 64 bit, the same effect happens running the 32 bit version so I'm thinking its windows rather than fractal extreme.