diff --git a/app/code/core/Mage/Eav/Model/Attribute/Data/Text.php b/app/code/core/Mage/Eav/Model/Attribute/Data/Text.php
index c48ed5932025f..15432541815dc 100644
--- a/app/code/core/Mage/Eav/Model/Attribute/Data/Text.php
+++ b/app/code/core/Mage/Eav/Model/Attribute/Data/Text.php
@@ -64,7 +64,7 @@ public function validateValue($value)
             $value = $this->getEntity()->getDataUsingMethod($attribute->getAttributeCode());
         }
 
-        if ($attribute->getIsRequired() && empty($value)) {
+        if ($attribute->getIsRequired() && empty($value) && $value !=='0') {
             $errors[] = Mage::helper('Mage_Eav_Helper_Data')->__('"%s" is a required value.', $label);
         }
 
diff --git a/app/code/core/Mage/Sales/Model/Order/Invoice/Total/Shipping.php b/app/code/core/Mage/Sales/Model/Order/Invoice/Total/Shipping.php
index 8ccba86065c7b..09eefb132d5c1 100644
--- a/app/code/core/Mage/Sales/Model/Order/Invoice/Total/Shipping.php
+++ b/app/code/core/Mage/Sales/Model/Order/Invoice/Total/Shipping.php
@@ -46,7 +46,7 @@ public function collect(Mage_Sales_Model_Order_Invoice $invoice)
              * Check shipping amount in previus invoices
              */
             foreach ($invoice->getOrder()->getInvoiceCollection() as $previusInvoice) {
-                if ($previusInvoice->getShippingAmount() && !$previusInvoice->isCanceled()) {
+                if ($previusInvoice->getShippingAmount() > 0 && !$previusInvoice->isCanceled()) {
                     return $this;
                 }
             }
diff --git a/dev/tests/unit/testsuite/Mage/Eav/Model/Attribute/Data/TextTest.php b/dev/tests/unit/testsuite/Mage/Eav/Model/Attribute/Data/TextTest.php
new file mode 100644
index 0000000000000..e7f438cf5a5ab
--- /dev/null
+++ b/dev/tests/unit/testsuite/Mage/Eav/Model/Attribute/Data/TextTest.php
@@ -0,0 +1,102 @@
+<?php
+/**
+ * Magento
+ *
+ * NOTICE OF LICENSE
+ *
+ * This source file is subject to the Open Software License (OSL 3.0)
+ * that is bundled with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * http://opensource.org/licenses/osl-3.0.php
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@magentocommerce.com so we can send you a copy immediately.
+ *
+ * DISCLAIMER
+ *
+ * Do not edit or add to this file if you wish to upgrade Magento to newer
+ * versions in the future. If you wish to customize Magento for your
+ * needs please refer to http://www.magentocommerce.com for more information.
+ *
+ * @category    Magento
+ * @package     Mage_Eav
+ * @subpackage  unit_tests
+ * @copyright   Copyright (c) 2012 Magento Inc. (http://www.magentocommerce.com)
+ * @license     http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
+ */
+class Mage_Eav_Model_Attribute_Data_TextTest extends PHPUnit_Framework_TestCase
+{
+
+    /**
+     * Text Model to be tested
+     * @var Mage_Eav_Model_Attribute_Data_Text|PHPUnit_Framework_MockObject_MockObject
+     */
+    protected $_model;
+    /**
+     * @var $_attribute Mage_Eav_Model_Entity_Attribute_Abstract|PHPUnit_Framework_MockObject_MockObject
+     */
+    protected $_attribute;
+    protected function setUp()
+    {
+        $this->_model = $this->getMock('Mage_Eav_Model_Attribute_Data_Text', array('getAttribute'), array(), '', false);
+        $attributeData = array(
+            'store_label' => 'Test',
+            'attribute_code' => 'test',
+            'is_required' => 1,
+            'validate_rules' => array(
+                'min_text_length' => 0,
+                'max_text_length' => 0,
+                'input_validation' => 0
+            )
+        );
+
+        /** @var $model Mage_Core_Model_Abstract */
+        $attribute = $this->getMock('Mage_Core_Model_Abstract', null, array($attributeData));
+
+        $this->_attribute = $attribute;
+        $this->_model->expects($this->any())
+            ->method('getAttribute')
+            ->will($this->returnValue($this->_attribute));
+        $helper = $this->getMockBuilder('Mage_Core_Helper_String')
+            ->setMethods(array('__'))
+            ->disableOriginalConstructor()
+            ->getMock();
+        $helper->expects($this->any())
+            ->method('__')
+            ->will($this->returnArgument(0));
+        Mage::register('_helper/Mage_Eav_Helper_Data', $helper);
+        Mage::register('_helper/Mage_Core_Helper_String', $helper);
+
+
+    }
+
+    protected function tearDown()
+    {
+        $this->_model = null;
+        Mage::unregister('_helper/Mage_Eav_Helper_Data');
+        Mage::unregister('_helper/Mage_Core_Helper_String');
+    }
+
+    /**
+     * This test is to check the change made to validateValue.
+     * A bug was found where a text attribute that has is_required==1
+     * would not accept the string value of "0" (zero) as an input.
+     * That bug was fixed.
+     * @covers Mage_Eav_Model_Attribute_Data_Text::validateValue
+     * @param string|int|float|array $value
+     * @param string|int|float|array $expectedResult
+     * @dataProvider dataGetValuesAndResults
+     */
+    public function testValidateValue($value, $expectedResult)
+    {
+        $this->assertEquals($expectedResult, $this->_model->validateValue($value));
+    }
+
+    public static function dataGetValuesAndResults()
+    {
+        return array(
+            array("0",true), //The string value of zero should be a valid input
+            array(0, array('"%s" is a required value.')) //Integer value of zero remains invalid
+        );
+    }
+}
\ No newline at end of file
diff --git a/dev/tests/unit/testsuite/Mage/Sales/Model/Order/Invoice/Total/ShippingTest.php b/dev/tests/unit/testsuite/Mage/Sales/Model/Order/Invoice/Total/ShippingTest.php
new file mode 100644
index 0000000000000..fd2269c1fa1b0
--- /dev/null
+++ b/dev/tests/unit/testsuite/Mage/Sales/Model/Order/Invoice/Total/ShippingTest.php
@@ -0,0 +1,91 @@
+<?php
+/**
+ * Magento
+ *
+ * NOTICE OF LICENSE
+ *
+ * This source file is subject to the Open Software License (OSL 3.0)
+ * that is bundled with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * http://opensource.org/licenses/osl-3.0.php
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@magentocommerce.com so we can send you a copy immediately.
+ *
+ * DISCLAIMER
+ *
+ * Do not edit or add to this file if you wish to upgrade Magento to newer
+ * versions in the future. If you wish to customize Magento for your
+ * needs please refer to http://www.magentocommerce.com for more information.
+ *
+ * @category    Magento
+ * @package     Mage_Sales
+ * @subpackage  unit_tests
+ * @copyright   Copyright (c) 2012 Magento Inc. (http://www.magentocommerce.com)
+ * @license     http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
+ */
+class Mage_Sales_Model_Order_Invoice_Total_ShippingTest extends PHPUnit_Framework_TestCase
+{
+    /**
+     * Invoice to be passed to the collect method in testCollect
+     * @var Mage_Sales_Model_Order_Invoice $_invoice
+     */
+    protected $_invoice;
+
+    /**
+     * Order to be returned when calling 'getOrder' inside collect method.
+     * @var Mage_Sales_Model_Order $_order
+     */
+    protected $_order;
+
+
+    protected function setUp()
+    {
+        $this->_invoice = $this->getMock('Mage_Sales_Model_Order_Invoice', array('getOrder'), array(), '', false);
+        $this->_order = $this->getMock('Mage_Sales_Model_Order', array('getInvoiceCollection'), array(),'',false);
+
+        $this->_invoice->expects($this->any())
+            ->method('getOrder')
+            ->will($this->returnValue($this->_order));
+    }
+    /**
+     * @covers Mage_Sales_Model_Order_Invoice_Total_Shipping::collect
+     * @param $collection array
+     * @param $shippingAmount float
+     * @dataProvider dataGetValuesAndResults
+     */
+    public function testCollect($collection, $shippingAmount)
+    {
+        $temp_collection = array();
+        foreach($collection as $tempShippingAmount){
+            $temp_invoice = $this->getMock('Mage_Sales_Model_Order_Invoice', null, array(), '', false);
+            $temp_invoice->setShippingAmount($tempShippingAmount);
+            $temp_collection[] = $temp_invoice;
+        }
+
+        $this->_order->expects($this->any())
+            ->method('getInvoiceCollection')
+            ->will($this->returnValue($temp_collection));
+        $this->_order->setData('shipping_amount',$shippingAmount);
+        $this->_order->setData('invoice_collection', $collection);
+        $total = new Mage_Sales_Model_Order_Invoice_Total_Shipping();
+        $total->collect($this->_invoice);
+        $this->assertEquals($this->_invoice->getShippingAmount(), $this->_order->getShippingAmount());
+
+
+    }
+
+    public static function dataGetValuesAndResults()
+    {
+        return array(
+            array(
+                array("0.0000")
+                ,10.00
+            ),
+            array(
+                array("10.000"),
+                0
+            )
+        );
+    }
+}
\ No newline at end of file