Hi Yoram,
Check out this related E2E forum thread: http://e2e.ti.com/support/data_converters/precision_data_converters/f/73/p/271646/956861.aspx#956861. There is an attached excel spreadsheet that graphs the SINC + FIR filter response.
The scaling numbers normalize the sum of the filter coefficients to 1. Also "134217728" is a typo, it should be "1/34217728".
Best Regards,
Chris