I enclosed the complete content of the prg.

>Are you sure you're running against exactly the same database?
>
>In other words, the only thing that may cause this behavior is
>
>1. Wrong date formats
>
>2. Different data sets
>
>3. Different SET DELETED setting.
>
>I see no other way the results will be different except for also a corrupted index, may be.

LOCAL lvReturned, lcUtv
SET DELETED ON

lnSess = ASESSIONS(laSess)
FOR lnCnt = 1 TO lnSess
	SET DATASESSION TO (laSess[lnCnt])
		IF TXNLEVEL() > 0
		   DO WHILE TXNLEVEL() > 0
		     ROLLBACK 
		   ENDDO
		ENDIF
	lnCntUsed = AUSED(laUsed)
	FOR lnSessCnt = 1 TO lnCntUsed
		SELECT(laUsed[lnsessCnt,2])
			IF CURSORGETPROP('Buffering')>1
				TABLEREVERT(.T.)
			ENDIF
			USE
	NEXT
NEXT

SET PATH TO 'D:\ElszOdosz\prg' ADDITIVE

lcUtv = "D:\ElszOdosz\data\bp_eng.dbf"
IF FILE("D:\ElszOdosz\data\bp_eng.cdx")
		IF USED("bp_eng")
    		USE
    	ENDIF 
    lvReturned = rem_cdx(lcUtv)
    WAIT 'Bp_eng >> '+lvReturned WINDOW NOWAIT 	
    SELECT 0
    DELETE FILE D:\ElszOdosz\data\bp_eng.cdx
	USE D:\ElszOdosz\data\bp_eng IN 1 EXCLUSIVE
  ELSE
    USE D:\ElszOdosz\data\bp_eng IN 1 EXCLUSIVE
ENDIF
SELECT 1

lcUtv = "D:\ElszOdosz\data\bp_tetel.dbf"
IF FILE("D:\ElszOdosz\data\bp_tetel.cdx")
		IF USED("bp_tetel")
    		USE
    	ENDIF 
    lvReturned = rem_cdx(lcUtv)
    WAIT 'Bp_tetel >> '+lvReturned WINDOW NOWAIT 	
    SELECT 0
    DELETE FILE D:\ElszOdosz\data\bp_tetel.cdx
	USE D:\ElszOdosz\data\bp_tetel IN 2 EXCLUSIVE
  ELSE
    USE D:\ElszOdosz\data\bp_tetel IN 2 EXCLUSIVE
ENDIF
SELECT 2

lcUtv = "D:\ElszOdosz\data\bp_fej.dbf"
IF FILE("D:\ElszOdosz\data\bp_fej.cdx")
		IF USED("bp_fej")
    		USE
    	ENDIF 
    lvReturned = rem_cdx(lcUtv)
    WAIT 'Bp_fej >> '+lvReturned WINDOW NOWAIT 	
    SELECT 0
    DELETE FILE D:\ElszOdosz\data\bp_fej.cdx
	USE D:\ElszOdosz\data\bp_fej IN 3 EXCLUSIVE
  ELSE
    USE D:\ElszOdosz\data\bp_fej IN 3 EXCLUSIVE
ENDIF
SELECT 3

lcUtv = "D:\ElszOdosz\uh\bp_eng.dbf"
IF FILE("D:\ElszOdosz\uh\bp_eng.cdx")
		IF USED("bp_eng_uh")
    		USE
    	ENDIF 
    lvReturned = rem_cdx(lcUtv)
    WAIT 'Bp_eng_uh >> '+lvReturned WINDOW NOWAIT 	
    SELECT 0
    DELETE FILE D:\ElszOdosz\uh\bp_eng.cdx
	USE D:\ElszOdosz\uh\bp_eng IN 7 ALIAS bp_eng_uh EXCLUSIVE
  ELSE
	USE D:\ElszOdosz\uh\bp_eng IN 7 ALIAS bp_eng_uh EXCLUSIVE
ENDIF
SELECT 7
 
lcUtv = "D:\ElszOdosz\ut\bp_eng.dbf"
IF FILE("D:\ElszOdosz\ut\bp_eng.cdx")
		IF USED("bp_eng_ut")
    		USE
    	ENDIF 
    lvReturned = rem_cdx(lcUtv)
    WAIT 'Bp_eng >> '+lvReturned WINDOW NOWAIT 	
    SELECT 0
    DELETE FILE D:\ElszOdosz\ut\bp_eng.cdx
	USE D:\ElszOdosz\ut\bp_eng IN 4 ALIAS bp_eng_ut EXCLUSIVE
  ELSE
    USE D:\ElszOdosz\ut\bp_eng IN 4 ALIAS bp_eng_ut EXCLUSIVE
ENDIF
SELECT 4

*************************************
*									*
*   ALÁÍRÁS ALAPJÁN LEKÉRDEZVE		*
*									*
*************************************

lcDateInd = {^2010.01.01 00:00:00}
lcDateErk = {^2010.02.01 00:00:00}
lcDateStor = {^2000.01.01 00:00:00}

******************************
**UE eseti
**Összes UE eseti eng
SELECT bp_eng.engkod, bp_tetel.brutto_ar;
from bp_eng;
where bp_eng.alairva >= lcDateInd;
AND bp_eng.alairva < lcDateErk;
AND bp_eng.stornozva < lcDateStor; 
AND bp_eng.tipus = "1";
into cursor osszesUE1


*Egyszerű
SELECT bp_eng.engkod,  bp_tetel.brutto_ar;
from bp_eng;
LEFT JOIN bp_tetel;
on ALLTRIM(bp_eng.engkod) == ALLTRIM(bp_tetel.engedely);
where bp_eng.alairva >= lcDateInd;
AND bp_eng.alairva < lcDateErk;
AND bp_eng.stornozva < lcDateStor; 
AND bp_eng.tipus = "1"; 
AND bp_eng.szelesseg <= 3.2; 
AND bp_eng.magassag <= 4.2; 
AND bp_eng.hossz <= 22; 
AND bp_eng.ossztomeg <= 50000; 
into cursor egyszUE

*bonyolult
SELECT bp_eng.engkod,  bp_tetel.brutto_ar;
from bp_eng;
LEFT JOIN bp_tetel;
on ALLTRIM(bp_eng.engkod) == ALLTRIM(bp_tetel.engedely);
where bp_eng.alairva >= lcDateInd;
AND bp_eng.alairva < lcDateErk;
AND bp_eng.stornozva < lcDateStor; 
AND bp_eng.tipus = "1"; 
AND (bp_eng.szelesseg > 3.2; 
OR bp_eng.magassag > 4.2; 
OR bp_eng.hossz > 22; 
OR bp_eng.ossztomeg > 50000); 
AND bp_eng.engkod NOT in (SELECT bp_eng.engkod; 
from bp_eng; 
where bp_eng.alairva >= lcDateInd;
AND bp_eng.alairva < lcDateErk;
AND bp_eng.stornozva < lcDateStor; 
AND bp_eng.tipus = "1"; 
AND bp_eng.szelesseg > 4; 
OR bp_eng.magassag > 4.5; 
OR bp_eng.hossz > 35; 
OR bp_eng.ossztomeg > 80000); 
into cursor bonyUE


*különösen bonyolult
SELECT bp_eng.engkod, bp_tetel.brutto_ar;
from bp_eng;
LEFT JOIN bp_tetel;
on ALLTRIM(bp_eng.engkod) == ALLTRIM(bp_tetel.engedely);
where bp_eng.alairva >= lcDateInd;
AND bp_eng.alairva < lcDateErk;
AND bp_eng.stornozva < lcDateStor; 
AND bp_eng.tipus = "1"; 
AND (bp_eng.szelesseg > 4; 
OR bp_eng.magassag > 4.5; 
OR bp_eng.hossz > 35; 
OR bp_eng.ossztomeg > 80000); 
into cursor kulbonyUE


**************
**UH
**Összes UH eng

SELECT count(bp_eng_uh.engkod) as db;
from bp_eng_uh;
where bp_eng_uh.alairva >= lcDateInd;
AND bp_eng_uh.alairva < lcDateErk;
AND bp_eng_uh.stornozva < lcDateStor;
into cursor osszesUH

SELECT count(bp_eng_uh.engkod) as db;
from bp_eng_uh;
where bp_eng_uh.alairva >= lcDateInd;
AND bp_eng_uh.alairva < lcDateErk;
AND bp_eng_uh.stornozva > lcDateStor;
AND bp_eng_uh.tipus = "1";
into cursor osszesUH

*Egyszerű
SELECT count(bp_eng_uh.engkod) as db;
from bp_eng_uh;
where bp_eng_uh.alairva >= lcDateInd;
AND bp_eng_uh.alairva < lcDateErk;
AND bp_eng_uh.stornozva < lcDateStor; 
AND bp_eng_uh.tipus = "1"; 
AND bp_eng_uh.szelesseg <= 3.2; 
AND bp_eng_uh.magassag <= 4.2; 
AND bp_eng_uh.hossz <= 22; 
AND bp_eng_uh.ossztomeg <= 50000; 
into cursor egyszUH

*bonyolult
SELECT count(bp_eng_uh.engkod) as db;
from bp_eng_uh;
where bp_eng_uh.alairva >= lcDateInd;
AND bp_eng_uh.alairva < lcDateErk;
AND bp_eng_uh.stornozva < lcDateStor; 
AND bp_eng_uh.tipus = "1"; 
AND (bp_eng_uh.szelesseg > 3.2; 
OR bp_eng_uh.magassag > 4.2; 
OR bp_eng_uh.hossz > 22; 
OR bp_eng_uh.ossztomeg > 50000); 
AND bp_eng_uh.engkod NOT in (SELECT bp_eng_uh.engkod; 
from bp_eng_uh; 
where bp_eng_uh.alairva >= lcDateInd;
AND bp_eng_uh.alairva < lcDateErk;
AND bp_eng_uh.stornozva < lcDateStor; 
AND bp_eng_uh.tipus = "1"; 
AND bp_eng_uh.szelesseg > 4; 
OR bp_eng_uh.magassag > 4.5; 
OR bp_eng_uh.hossz > 35; 
OR bp_eng_uh.ossztomeg > 80000); 
into cursor bonyUH

*különösen bonyolult
SELECT count(bp_eng_uh.engkod) as db;
from bp_eng_uh;
where bp_eng_uh.alairva >= lcDateInd;
AND bp_eng_uh.alairva < lcDateErk;
AND bp_eng_uh.stornozva < lcDateStor; 
AND bp_eng_uh.tipus = "1"; 
AND (bp_eng_uh.szelesseg > 4; 
OR bp_eng_uh.magassag > 4.5; 
OR bp_eng_uh.hossz > 35; 
OR bp_eng_uh.ossztomeg > 80000); 
into cursor kulbonyUH

**************
**UT
**Összes UT eng
SELECT count(bp_eng_ut.engkod) as db;
from bp_eng_ut;
where bp_eng_ut.alairva >= lcDateInd;
AND bp_eng_ut.alairva < lcDateErk;
AND bp_eng_ut.stornozva < lcDateStor;
AND bp_eng_ut.tipus = "1";
into cursor osszesUt

*Egyszerű
SELECT count(bp_eng_ut.engkod) as db;
from bp_eng_ut;
where bp_eng_ut.alairva >= lcDateInd;
AND bp_eng_ut.alairva < lcDateErk;
AND bp_eng_ut.stornozva < lcDateStor; 
AND bp_eng_ut.tipus = "1"; 
AND bp_eng_ut.szelesseg <= 3.2; 
AND bp_eng_ut.magassag <= 4.2; 
AND bp_eng_ut.hossz <= 22; 
AND bp_eng_ut.ossztomeg <= 50000; 
into cursor egyszUt

*bonyolult
SELECT count(bp_eng_ut.engkod) as db;
from bp_eng_ut;
where bp_eng_ut.alairva >= lcDateInd;
AND bp_eng_ut.alairva < lcDateErk;
AND bp_eng_ut.stornozva < lcDateStor; 
AND bp_eng_ut.tipus = "1"; 
AND (bp_eng_ut.szelesseg > 3.2; 
OR bp_eng_ut.magassag > 4.2; 
OR bp_eng_ut.hossz > 22; 
OR bp_eng_ut.ossztomeg > 50000); 
AND bp_eng_ut.engkod NOT in (SELECT bp_eng_ut.engkod; 
from bp_eng_ut; 
where bp_eng_ut.alairva >= lcDateInd;
AND bp_eng_ut.alairva < lcDateErk;
AND bp_eng_ut.stornozva < lcDateStor; 
AND bp_eng_ut.tipus = "1"; 
AND bp_eng_ut.szelesseg > 4; 
OR bp_eng_ut.magassag > 4.5; 
OR bp_eng_ut.hossz > 35; 
OR bp_eng_ut.ossztomeg > 80000); 
into cursor bonyUt

*különösen bonyolult
SELECT count(bp_eng_ut.engkod) as db;
from bp_eng_ut;
where bp_eng_ut.alairva >= lcDateInd;
AND bp_eng_ut.alairva < lcDateErk;
AND bp_eng_ut.stornozva < lcDateStor; 
AND bp_eng_ut.tipus = "1"; 
AND (bp_eng_ut.szelesseg > 4; 
OR bp_eng_ut.magassag > 4.5; 
OR bp_eng_ut.hossz > 35; 
OR bp_eng_ut.ossztomeg > 80000); 
into cursor kulbonyUt


*************************
**UE éves
**Összes UE éves eng
SELECT count(bp_eng.engkod) as db;
from bp_eng;
where bp_eng.alairva >= lcDateInd;
AND bp_eng.alairva < lcDateErk;
AND bp_eng.stornozva < lcDateStor;
AND bp_eng.tipus # "1";
into cursor osszUE_ev

*teljes közúthálózat
SELECT count(bp_eng.engkod) as db;
from bp_eng;
where bp_eng.alairva >= lcDateInd;
AND bp_eng.alairva < lcDateErk;
AND bp_eng.stornozva < lcDateStor; 
AND bp_eng.tipus # "1";
AND bp_eng.utvtipus = "2"; 
into cursor teljkozUE;

*főúthálózat
SELECT count(bp_eng.engkod) as db;
from bp_eng;
where bp_eng.alairva >= lcDateInd;
AND bp_eng.alairva < lcDateErk;
AND bp_eng.stornozva < lcDateStor; 
AND bp_eng.tipus # "1";
AND bp_eng.utvtipus = "3"; 
into cursor foutUE;

*kijelölt út
*Egyszerű
SELECT count(bp_eng.engkod) as db;
from bp_eng;
where bp_eng.alairva >= lcDateInd;
AND bp_eng.alairva < lcDateErk;
AND bp_eng.stornozva < lcDateStor; 
AND bp_eng.tipus # "1";
AND bp_eng.utvtipus = "0"; 
into cursor kijutUE

*Kistérségi
*Egyszerű
SELECT count(bp_eng.engkod) as db;
from bp_eng;
where bp_eng.alairva >= lcDateInd;
AND bp_eng.alairva < lcDateErk;
AND bp_eng.stornozva < lcDateStor; 
AND bp_eng.tipus # "1";
AND bp_eng.utvtipus = "1"; 
into cursor kisterUE


*************************
**UT éves
**Összes UT éves eng
SELECT count(bp_eng_ut.engkod) as db;
from bp_eng_ut;
where bp_eng_ut.alairva >= lcDateInd;
AND bp_eng_ut.alairva < lcDateErk;
AND bp_eng_ut.stornozva < lcDateStor;
AND bp_eng_ut.tipus # "1";
into cursor osszUT_ev

*teljes közúthálózat
SELECT count(bp_eng_ut.engkod) as db;
from bp_eng_ut;
where bp_eng_ut.alairva >= lcDateInd;
AND bp_eng_ut.alairva < lcDateErk;
AND bp_eng_ut.stornozva < lcDateStor; 
AND bp_eng_ut.tipus # "1";
AND bp_eng_ut.utvtipus = "2"; 
into cursor teljkozUT

*főúthálózat
SELECT count(bp_eng_ut.engkod) as db;
from bp_eng_ut;
where bp_eng_ut.alairva >= lcDateInd;
AND bp_eng_ut.alairva < lcDateErk;
AND bp_eng_ut.stornozva < lcDateStor; 
AND bp_eng_ut.tipus # "1";
AND bp_eng_ut.utvtipus = "3"; 
into cursor foutUT

*kijelölt út
*Egyszerű
SELECT count(bp_eng_ut.engkod) as db;
from bp_eng_ut;
where bp_eng_ut.alairva >= lcDateInd;
AND bp_eng_ut.alairva < lcDateErk;
AND bp_eng_ut.stornozva < lcDateStor; 
AND bp_eng_ut.tipus # "1";
AND bp_eng_ut.utvtipus = "0"; 
into cursor kijutUT

*Kistérségi
*Egyszerű
SELECT count(bp_eng_ut.engkod) as db;
from bp_eng_ut;
where bp_eng_ut.alairva >= lcDateInd;
AND bp_eng_ut.alairva < lcDateErk;
AND bp_eng_ut.stornozva < lcDateStor; 
AND bp_eng_ut.tipus # "1";
AND bp_eng_ut.utvtipus = "1"; 
into cursor kisterUT