MPA for Payables Invoice

Hi

We have configured to use MPA to amortize the prepaid expenses to spread accross multiple periods.

We have created Invoice as below

a) deferred option enabled at Invoice lines with period 11-OCT-2014 to 10-OCT-2015
b) validated and accounted (using action > validate and create accounting)
c) System calculated the amortization upto 31-Mar-2015 (since the accounting calander was defined till this period)
d) we defined the GL Periods in the accounting calendar
e) amortization is not recalculating which is to be spread over upto 10-OCT-2015

Please provide us the solution for system to recalculate the expenses for the complete period since we have defined the future periods