I found the solution to this is to add 3rd argument in function call get_customer_trans() in /includes/ui/allocation_cart.inc as below on Line#399

$trans = get_customer_trans($_SESSION['alloc']->allocs[$counter]->type_no, $_SESSION['alloc']->allocs[$counter]->type, $_SESSION['alloc']->person_id);

This is what the system report:

/var/www/numerillos.com.ar/sales/includes/db/cust_trans_db.inc:213:    display_backtrace()
/var/www/numerillos.com.ar/includes/ui/allocation_cart.inc:399:    get_customer_trans('762','0')
/var/www/numerillos.com.ar/sales/customer_payments.php:222:    check_allocations()
/var/www/numerillos.com.ar/sales/customer_payments.php:236:    can_process()
ERROR DE BASE DE DATOS : duplicate debtor transactions found for given params
sql that failed was : SELECT trans.*,ov_amount+ov_gst+ov_freight+ov_freight_tax+ov_discount AS Total,cust.name AS DebtorName, cust.address, cust.curr_code, cust.tax_id, trans.prep_amount>0 as prepaid,com.memo_, branch.* FROM 0_debtor_trans trans LEFT JOIN 0_comments com ON trans.type=com.type AND trans.trans_no=com.id LEFT JOIN 0_shippers ON 0_shippers.shipper_id=trans.ship_via, 0_debtors_master cust, 0_cust_branch branch WHERE trans.trans_no='762' AND trans.type='0' AND trans.debtor_no=cust.debtor_no AND branch.branch_code = trans.branch_code