PT Prima import error

When I import my hand histories from RoyalVegasPoker(Prima Network) I get an error that doesnt allow me to import all of the hands...

Starting import of 128 hand(s)

Import Finished With Errors - The import finished but there were errors. The error messages were written to a file named c:\program files\poker tracker v2\PRIMA_ErrorFile_20050920_175432.txt - 127 hand(s) were imported.

There error file reads - Prima/Ladbrokes hand history error - duplicate seats found in hand history for game #495909704.

What does this mean and how can i fix it? I don't want to skew my database.

Thanks