Hmm...This issue has been resolved.
The reason is that you have to make sure that the columns specified in the primary key should be the first N columns in the table. N is equal to the number of columns the primary key has.
Suppose you have a table call TEST1 with columns of col1, col2, col3, col4, col5. And you create a primary key on (col1, col4, col5). If you update on col2 or col3, or you delete a row, duplicate error will occur.
You have two options the fix it. one is to ask the db administrator of the source system to modify the table structure. one is to modify it in the SLT table settings(LTRS).
Chong