Need help for reading the value of a fieldref

Hi. I use Navision 3.70 and I have the following problem.
fref --> fieldref
ref --> RecordRef

Here's the code of a function of a codeunit. The function's arguments as
tableno and position.

ref_mod(tableno : Integer;position : Text [250])

ref.OPEN(tableno);
ref.SETPOSITION(position);
fref := ref.FIELD(1);
message(format(fref.value));

Here's the deal: if the field is the primary key,is shows its value. If it is any other field it shows its initial value ('' for string, 0 for option etc). I can't get the real value of the specific record. :evil:
Does anyone know why this happens? How can I get the real value?

PS. Here's a usual call of ref_mod :
ref_mod(9,'Code=const(ES)');

PS2. Thanks for reading this.