Saving nodes in spectre include file

I am trying to adjust my list of saved nodes in a simulation depending on an ADE design variable.  i.e. if a certain part of a circuit is enabled for a simulation, the nodes in that part will get saved.

I have been trying to do this using a spectre include file within ADE-XL to define nodes to save.

 //start

save I131.*                //save all nodes inside instance I131

// This section is where I was trying to save depending on a design variable

// Couldn't get it to work

// diff_ac is a design variable in ADE

if ( diff_ac < 0.5 ) {

save I129.*

} else {

save I128.*

} 

//end 

The first save statement works, so the script is definitely getting read in. But, neither of the save statements in the if() statement working.  No errors, but no save either.  My understanding is that ADE design variables become parameters in spectre.  Is my if() statement used correctly?  Do I need to reference the design variables in a different way?