Discount calculation issue causing cart to show wrong values

[hemal108]

FILE: Web/Ppfix/Model/Cart.php
Method _validate()

Lines
if (!$this->_isDiscountAsItem) {
$discountAmount = Mage::helper('ppfix')->getExchangeRate($this->_totals[self::TOTAL_DISCOUNT]);
$sum -= $discountAmount;
// $sum -= $this->_totals[self::TOTAL_DISCOUNT];
}

// PayPal requires to have discount less than items subtotal
if (!$this->_isDiscountAsItem) {
$this->_areTotalsValid = round($discountAmount, 4) < round($itemsSubtotal, 4);
} else {
$this->_areTotalsValid = $itemsSubtotal > 0.00001;
}