Are there special considerations for referencing stored member formulas in a member block??

Summary:

I have a stored account called AcctX with a member formula: AcctX = 1;

If I execute this script that references it. is does not calculate a value:

FIX ("No Year","BegBalance", E123,Budget,Working)
  AcctX(
  	IF("store" <> #missing)
             AcctX;
         ENDIF)
ENDFIX

I know it's not the "IF" because if I do an assignment instead (below) it does calculate:

FIX ("No Year","BegBalance", E123,Budget,Working)
  AcctX(
  	IF("store" <> #missing)
             AcctX = 1;
         ENDIF)
ENDFIX

Referencing the stored member without the IF also works:

FIX ("No Year","BegBalance", E123,Budget,Working)
    AcctX;        
ENDFIX

Is there something special about referencing a stored member formula within a member block I'm not considering?