duplicate record on table

table of delphi 3 used with interbase 4.51.

when I do a range the result on the screen of this range is that
the number of the records is more than the real number of records
on the database, in the grid the records are duplicated or triplicated
or ...

please for more informations replay to  davsi...@col.it or
nicosi...@col.it

thanks.