I cannot find out what is wrong with my _genxtab. Anybody can tell me?

I created a test2.dbf and program a.prg

DISPLAY STRUCTURE of test2.dbf gives :

Structure for table: c:\twy\test2.dbf
Number of data records: 6
Date of last update: 21/07/1997
Code Page: 0
Field Field Name Type Width Dec Index Collate
1 TT1 Character 10
2 TT2 Character 1
3 TT3 Character 10
** Total ** 22

DISPLAY ALL for test2.dbf gives:

Record# TT1 TT2 TT3
1 11 1 S
2 11 2 M
3 11 3 L
4 22 1 M
5 22 2 L
6 33 1 L

Codes for a.prg:

SELECT TT1,TT2,TT3 ;
FROM TEST2 ;
GROUP BY TT1,TT2 ;
ORDER BY TT1,TT2 ;
INTO CURSOR SYS(2015)
DO (_GENXTAB) WITH 'QUERY1'
BROW norm


DISPLAY ALL FOR 'Query1' gives:

Record# TT1 C_1 C_2 C_3
1 11
2 22
3 33


The result is empty? What can be the reason?

Tai