Fix total order price shown on Phonegap app with admin panel made with Yii system

My delivery system made with Yii has voucher and points system and there is a PhoneGap customer app. The system has paypal payment integrated. On paypal is possible setup additional tax that increases the total order price higher than if choose cash payment. If an order has total price $100 (product + delivery tax), on checkout when choose the cash payment method the order total price will be $100 and after apply voucher ($5 discount) or redeem points ($5 discount) the total order will be $95, for example. The problem is: If an order has total price $100 (product + delivery tax), on checkout when choose the paypal payment method the order total price will be $110 because the paypal additional tax (increases $10 on total order price). But after apply voucher or redeem points ($5 discount) the total order that should be $105 is beng shown $95 that is cash payment method ($100) less the voucher or point discount ($5). An important detail: Even if the checkout is showing this problem and i click on NEXT, the paypal payment screen opens and the total order is corrected there on paypal screen so i understand that the problem is on how the order total price is shown. After fix this problem i will have more services for this delivery system but my urgency is for fixing it.