Check this code in Command window after DECLARE:

? SetBin(set('prin',2),'bla-bla-bla') && 0 - Failed
? SetBin(set('prin',2),GetBin(set('prin',2))) && (-1) - Ok

If it does not work name version OS, model of the printer and the version of the driver. If it is carried out, check up presence of other changes of the original.