Debugging some old, long and complicated code I have found curious problem. System generates extremely long strings (supposedly unique), but stores in appropriate temp table not literal results but string check sums using SYS(2007) function. However, sometimes SYS(2007) yields the same value for absolutely different strings and whole algorithm fails. Is it right behaviour for SYS(2007) (I have never used it before) and how to fix the problem? TIA.