Hello Victor,
Couple thoughts:
Your 1st amortization should be on 16/05/2014 and that should result in an amount close to what you are expecting.
Your last amortization should be on 31/12/2014 and that should in amount of 5M (provided no amortizations have been posted before).
Also, in amortization procedure setting, you should probably have "Adjust Effective interest rate immediately" because the "Constant effective interest rate" setting is for securities with installment repayment (from your example, it did not seem like yours was that case).
Let us know.
Mani