Duplicate entries for the same card on import.

I am having a strange result when importing cards via CSV file. The CSV file I included additional copies of a card I already had in my inventory. In this case I had 5 Vampire Nighthawks from Magic 2013 already in my inventory and was importing an additional 2 within the CSV file. Instead of my inventory having 7 copies of Vampire Nighthawk from M13, it shows:

5    0    Vampire Nighthawk                    Magic 2013    Near Mint    English
2    0    Vampire Nighthawk                    Magic 2013    Near Mint    English

Is there anyway to correct this besides manuall finding and fixing all these occurrences?