Make sure that your import records is referencing the correct file and table. It might be referencing a different copy of the file.
When you say file do you mean the Excel Spreadsheet or the Filemaker Database?
In Filemaker the database only shows one Table which has the fields I need so I'm not sure how it is reffering to a previous version of the Table
I started again created a new Database and it is ok now. Seems if you delete fields from a table it messes it up but if you add fields it doesn't cause any problem.