Pankaj,
I had similar issue earlier in my project when working with internal audit team,
they give users who need to lock but they come back saying user is not locked actually its locked when you check in SU01 you can able to see that, so dont depend on SUIM reports which will not give you accurate report, i dont know why but it happens
.
Better try to get it from USR and USH tables.
Regards,
RK