It looks like channels being passed from one CHOP to another are losing precision.
I have an expression CHOP connected to a math CHOP and then another math CHOP. When the values being fed from the expression CHOP got to be less than -1.0 e^5 then the following math CHOP would take the value as 0.
Running the same formula that the 3 CHOPs were doing in a single expression CHOP works fine:
1.0 / me.inputVal * parent().panel.screenh * .5 * me.inputs