WINDOWS 2000 ORACLE9I

I found the following problem when tranfering Schema A to B,

EXP SYSTEM/AAA@DB1 OWNER=A FILE=A
IMP SYSTEM/BBB@DB2 FROMUSER=A TOUSER=B FILE=A

There is no object in USER B before import, and no error reported in EXP/IMP.

But when checking the TRIGGERS in USER B, I found the TABEL/VIEW OWNER of some triggers are still A.

What's the problem,pls advise.

THANKS