Today I faced same problem.
impdp, expdp log are showing same number of records but target database has more number of rows(duplicate) in few tables.
Source database version 10.2.0.4 and target database version is 220.127.116.11.
I loaded the same dump file again with same par file. it loaded successfully. According to oracle support. something has interfered between data load and index creation time when the data pump in progress.
Edited by: 931804 on Oct 11, 2012 2:35 AM