IMPORT DB2 Utility dropping records-what are the causes

Hi,
We are using IMPORT utility to import data into tables in unix scripts.It is not importing all the records but log showing that all the records imported.For Ex:25 records to be inserted, it inserts 18 records and it drops remaining.But in logs showing that all 25 records are imported.I have pasted logs below in blue color.This issue is not happening frequently very few times are happening.When I try to import data manually in the same table and same data during my analysis, it got imported with out any issues.Can you please help me what is the reason that for IMPORT utility dropping records?


Loader.ksh : 2013-04-04 10:14:51: db2 -c "IMPORT from /WORK/WLY_TBL_Data.IXF OF IXF MESSAGES /WORK/WLY_TBL_Data.log INSERT INTO REPORT.WLY_TBL " > /WORK/WLY_TBL_Data.out

Loader.ksh : 2013-04-04 10:14:51 : Import completed : 25 records inserted and 0 record(s) rejected. 0 record(s) were deleted before import.

DB20000I The SQL command completed successfully.

Thanks & regards,
YN