Can't add keyframes to Parameters

[photosbyiki]

I'm probably doing something terribly wrong.  I want to animate parameters in a Tyflow Operator.  However, I'm unable to.  Can you confirm that paramerter are Keyable and if so, what could be the problem here?  
I've tried with several operators, but the one I'm trying to animate is the Random Spread X Value =/- in the Spread Operator.
I've tried using the Auto Key and also right clicking on the parameter and Add Key.

Keyframes seem to be added but the values don't seem to be affected.