Hi,
If you are using the difference procedure for accrual, the final interest flow should not have posting into P & L, as accruals have already accounted for them, but would rather post into Balance sheet receivable on interest account to clear those accumulated accrual amount.
I think that you would need to change the account determination for the Interest Flow type to post such a way as
Bank Clearninga ccount/Receivable on interest.
hope that this helps
Taro