Voltage Counts Range 0-970

[Jefferson]

Now that we have slip rings on our swerve modules, we spend some time at the roll-over point of our analog encoders (the point where it rolls from 5V to 0V). We were surprised that there was significant "chatter" around this point and chalked it up to a bug in the PIDContoller to be found latter.
In trying to debug some different weirdness observed in crab, I started looking more closely at the values reported for GetAverageValue from the modules. I was surprised to find that the encoders never report anything greater than 970, but roll over all the way to 0.
A few things we checked:
Encoders are providing a full 0-5V output range.
GetValue provides the same range.
All four wheel modules on two robots exhibit the same "chatter" in the modules.

Of course we can rescale all of our calculations to 970, but I'd like to know why we aren't getting to 1024.

Has anybody seen anything like this before? We've not used the full range of our encoders before now.

Thanks