Qlik will always suppress duplicate rows. If all of the values in all of the columns are the same they will only show once.
If you have sum expressions for all values in the table then you will be fine, as the duplicate rows will have the values increased.
On the other hand, if you have values in as dimensions and these are also the same across two rows the duplicate will be removed, and your values will be less. This is obviously a bad thing.
The way you can avoid this happening is to have a dimension in your table with a unique value per row. If there is not one in the source data you can add one using the RowNo() function in the load script, e.g.
RowNo() as ID,
Adding this to your table should mean all rows display.