Strange system 3D rating changes

I installed FM12 yesterday through Steam. While setting up the preferences I noticed that the system 3D rating was at 5 stars. However, today I was again looking at the preferences and noticed the 3D rating has decreased by 1.5 stars. What might be the reason for this? The only thing I've done is added some additional graphics to the game like additional club logos and player pics, but somehow I doubt that these would affect the 3D rating.

Another question regarding preferences is how come I have to keep "Using Skin Cache" ticked in order to retain the color changes to the attributes? If it's not ticked, then they become reset to default colors. I also have "Always Reload Skin on Confirm" ticked. Should both of these options be ticked at all times?

I'd appreciate any help with this. Thanks.