MF calculate the "key"-field instead of the "value"-field in a Number-list field

This module is great idea behind and it really needed in many ways.

However, I have found great problem on calculating "values" from a Slider Field Module, and have not got it to work
Please advice?

When instead trying with to build a Number-list-field with values, the Math Field module is calculating on the fields "key-value" instead of "value"
Could it be something wrong here? - Who even should lead to answer on first question?

Hopefully with regards / Göran

Its also strange that "tokens" not showing any of the field-names inside the node-type when editing in a Math-Field-field?
And it would be grate if future release does, as i do i. e. the Rules module.