PostgreSQL batch inserts fail silent randomly

I have been using [Kettle](http://community.pentaho.com/projects/data-integration/) to import data from a SQL Server to PostgreSQL on AWS RDS and when I was enabling all of my foreign key constraints I realized that data was missing, often in the even hundreds. But checking the log of the Kettle job, it seems to be doing all read and writes correctly from a table of 1923 entries 2017/02/26 21:36:42 - Table output.5 - Finished processing (I=0, O=240, R=240, W=240, U=0, E=0) 2017/02/26 21:36:42 - Table output.3 - Finished processing (I=0, O=240, R=240, W=240, U=0, E=0) 2017/02/26 21:36:42 - Table output.7 - Finished processing (I=0, O=240, R=240, W=240, U=0, E=0) 2017/02/26 21:36:42 - Table output.6 - Finished processing (I=0, O=240, R=240, W=240, U=0, E=0) 2017/02/26 21:36:42 - Table output.1 - Finished processing (I=0, O=241, R=241, W=241, U=0, E=0) 2017/02/26 21:36:42 - Table output.2 - Finished processing (I=0, O=241, R=241, W=241, U=0, E=0) 2017/02/26 21:36:42 - Table output.4 - Finished processing (I=0, O=240, R=240, W=240, U=0, E=0) 2017/02/26 21:36:42 - Table output.0 - Finished processing (I=0, O=241, R=241, W=241, U=0, E=0) But when running the query count on Postgres I get 1423 entries, and similar behavior on maybe 10% of all tables I have transferred. As I don't have any prior experience in neither Kettle nor Postgres, what is it that can cause this issue?