Unable to change accounting distribution after doing a 2 way match prior to posting the voucher

Created a voucher using P4314 - 2 way match.  After finishing the voucher process I needed to change the accounting distribution.  I go to batch review and go to GL Distribution and the accounting fields are locked.  I tried using setting the processing options in P0400047 from blank to 1 in Processing Option in the Purchasing Tab for the voucher change message.  I still can't change the GL distribution. 

Is there a way to change the accounting distribution without having to reverse/delete the voucher, go back to the purchase order, change the accounting on the purchase order and do the 2 way match again?